Complement Inactivator Proteins
Complement C3b Inactivator Proteins
Complement C1 Inactivator Proteins
Complement C3
Complement Activation
Complement System Proteins
Complement C4
Complement C5
Complement C3b
Complement Pathway, Alternative
Receptors, Complement
Complement C2
Complement Pathway, Classical
Complement Factor B
Properdin
Complement C1q
Complement C9
Complement Factor H
Complement Activating Enzymes
Complement Membrane Attack Complex
Complement C3-C5 Convertases
Complement Inactivating Agents
Complement C3a
Complement C5a
Complement C6
Receptors, Complement 3b
Complement C1
Complement C4b
Anaphylatoxins
Complement C3d
Complement Fixation Tests
Complement C7
Complement C8
Complement C3c
Hemolysis
Receptors, Complement 3d
Complement Hemolytic Activity Assay
Complement C4a
Lysine Carboxypeptidase
Complement Factor D
Beta-Globulins
Complement Factor I
Complement C4b-Binding Protein
Complement C1s
Immunoelectrophoresis
Cytochrome P-450 CYP2B1
Chloromercurinitrophenols
Antigen-Antibody Complex
Angioedema
Complement C1r
Kaolin
Serum Globulins
Antigens, CD55
Antigens, CD59
Enzyme Inhibitors
Complement C5b
Capsular sialic acid limits C5a production on type III group B streptococci. (1/619)
The majority of type III group B streptococcus (GBS) human neonatal infections are caused by a genetically related subgroup called III-3. We have proposed that a bacterial enzyme, C5a-ase, contributes to the pathogenesis of neonatal infections with GBS by rapidly inactivating C5a, a potent pro-inflammatory molecule, but many III-3 strains do not express C5a-ase. The amount of C5a produced in serum following incubation with representative type III strains was quantitated in order to better understand the relationship between C5a production and C5a-ase expression. C5a production following incubation of bacteria with serum depleted of antibody to the bacterial surface was inversely proportional to the sialic acid content of the bacterial capsule, with the more heavily sialylated III-3 strains generating less C5a than the less-virulent, less-sialylated III-2 strains. The amount of C5a produced correlated significantly with C3 deposition on each bacterial strain. Repletion with type-specific antibody caused increased C3b deposition and C5a production through alternative pathway activation, but C5a was functionally inactivated by strains that expressed C5a-ase. The increased virulence of III-3 strains compared to that of III-2 strains results at least partially from the higher sialic acid content of III-3 strains, which inhibits both opsonophagocytic killing and C5a production in the absence of type-specific antibody. We propose that C5a-ase is not necessary for III-3 strains to cause invasive disease because the high sialic acid content of III-3 strains inhibits C5a production. (+info)Effects of a new C5a receptor antagonist on C5a- and endotoxin-induced neutropenia in the rat. (2/619)
A new C5a receptor antagonist, the cyclic peptide Phe-[Orn-Pro-D-cyclohexylalanine-Trp-Arg], (F-[OPdChaWR]), was tested for its ability to antagonize the neutropenic effects of both C5a and endotoxin in rats. Human recombinant C5a (2 microg kg(-1) i.v.) caused rapid neutropenia, characterized by an 83% decrease in circulating polymorphonuclear leukocytes (PMNs) at 5 min. Administration of F-[OPdChaWR] (0.3-3 mg kg(-1) i.v.), did not affect the levels of circulating PMNs but, when given 10 min prior to C5a, it inhibited the C5a-induced neutropenia by up to 70%. Administration of E. Coli lipopolysaccharide (LPS, 1 mg kg(-1) i.v.) also caused neutropenia with an 88% decrease in circulating PMNs after 30 min. When rats were pretreated with F-[OPdChaWR] (0.3 - 10 mg kg(-1) i.v.) 10 min prior to LPS, there was a dose-dependent antagonism of the neutropenia caused by LPS, with up to 69% reversal of neutropenia observed 30 min after LPS administration. These findings suggest that C5a receptor antagonists may have therapeutic potential in the many diseases known to involve either endotoxin or C5a. (+info)Endothelial targeting and enhanced antiinflammatory effects of complement inhibitors possessing sialyl Lewisx moieties. (3/619)
The complement inhibitor soluble complement receptor type 1 (sCR1) and a truncated form of sCR1, sCR1[desLHR-A], have been generated with expression of the selectin-reactive oligosaccharide moiety, sialyl Lewisx (sLex), as N-linked oligosaccharide adducts. These modified proteins, sCR1sLex and sCR1[desLHR-A]sLex, were assessed in the L-selectin- and P-selectin-dependent rat model of lung injury following systemic activation of complement by cobra venom factor and in the L-selectin-, P-selectin-, and E-selectin-dependent model of lung injury following intrapulmonary deposition of IgG immune complexes. In the cobra venom factor model, sCR1sLex and sCR1[desLHR-A]sLex caused substantially greater reductions in neutrophil accumulation and in albumin extravasation in lung when compared with the non-sLex-decorated forms. In this model, increased lung vascular binding of sCR1sLex and sCR1[desLHR-A]sLex occurred in a P-selectin-dependent manner, in contrast to the absence of any increased binding of sCR1 or sCR1[desLHR-A]. In the IgG immune complex model, sCR1[desLHR-A]sLex possessed greater protective effects relative to sCR1[desLHR-A], based on albumin extravasation and neutrophil accumulation. Enhanced protective effects correlated with greater lung vascular binding of sCR1[desLHR-A]sLex as compared with the non-sLex-decorated form. In TNF-alpha-activated HUVEC, substantial in vitro binding occurred with sCR1[desLHR-A]sLex (but not with sCR1[desLHR-A]). This endothelial cell binding was blocked by anti-E-selectin but not by anti-P-selectin. These data suggest that sLex-decorated complement inhibitors have enhanced antiinflammatory effects and appear to have enhanced ability to localize to the activated vascular endothelium. (+info)Inhibition of a membrane complement regulatory protein by a monoclonal antibody induces acute lethal shock in rats primed with lipopolysaccharide. (4/619)
Rats pretreated with traces of LPS developed acute fatal shock syndrome after i.v. administration of a mAb that inhibits the function of a membrane complement regulatory molecule. Such a shock was not observed after the administration of large amounts of LPS instead of the mAb following LPS pretreatment. The lethal response did not occur in rats depleted of either leukocytes or complement, and a C5a receptor antagonist was found to inhibit the reaction. Furthermore, LPS-treated rats did not suffer fatal shock following the injection of cobra venom factor, which activates complement in the fluid phase so extensively as to exhaust complement capacity. Therefore, complement activation on cell membranes is a requirement for this type of acute reaction. (+info)Epitope mapping of 10 monoclonal antibodies against the pig analogue of human membrane cofactor protein (MCP). (5/619)
Pig membrane cofactor protein (MCP; CD46) is a 50 000-60 000 MW glycoprotein that is expressed on a wide variety of cells, including erythrocytes. Pig MCP has cofactor activity for factor I-mediated cleavage of C3b and is an efficient regulator of the classical and alternative pathway of human and pig complement. A panel of 10 monoclonal antibodies (mAbs) was collected from two different laboratories; all of these mAbs were raised against pig leucocytes and all recognized the same complex banding pattern on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of erythrocyte membranes. All were shown to be reactive with pig MCP and were divided into four groups of mutually competitive antibodies based on competition studies for membrane-bound MCP and for soluble MCP, the latter by surface plasmon resonance (SPR) analysis. The antigenic properties of membrane-bound and soluble MCP were similar, although some interesting differences were revealed. None of the 10 mAbs were cross-reactive with human MCP and only one showed cross-reactivity with leucocytes from a panel of large mammals - a weak cross-reactivity with a subset of dog leucocytes. All antibodies in one of the epitope groups and some in a second epitope group were able to block the functional activity of pig MCP, as measured by inhibition of MCP-catalysed C3 degradation by factor I. (+info)Mechanisms of enhanced lung injury during sepsis. (6/619)
A major complication in sepsis is progressively impaired lung function and susceptibility to intrapulmonary infection. Why sepsis predisposes the lung to injury is not clear. In the current studies, rats were rendered septic by cecal ligation/puncture and evaluated for increased susceptibility to injury after a direct pulmonary insult (deposition of IgG immune complexes or airway instillation of lipopolysaccharide). By itself, cecal ligation/puncture did not produce evidence of lung injury. However, after a direct pulmonary insult, lung injury in septic animals was significantly enhanced. Enhanced lung injury was associated with increased accumulation of neutrophils in lung, enhanced production of CXC chemokines (but not tumor necrosis factor-alpha) in bronchoalveolar lavage fluids, and increased expression of lung vascular intercellular adhesion molecule-1 (ICAM-1). Complement depletion or treatment with anti-C5a abolished all evidence of enhanced lung injury in septic animals. When stimulated in vitro, bronchoalveolar lavage macrophages from septic animals had greatly enhanced CXC chemokine responses as compared with macrophages from sham-operated animals or from septic animals that had been complement depleted. These data indicate that the septic state causes priming of lung macrophages and suggest that enhanced lung injury in the septic state is complement dependent and related to increased production of CXC chemokines. (+info)Interaction between protein S and complement C4b-binding protein (C4BP). Affinity studies using chimeras containing c4bp beta-chain short consensus repeats. (7/619)
Human C4b-binding protein (C4BP) is a regulator of the complement system and plays an important role in the regulation of the anticoagulant protein C pathway. C4BP can bind anticoagulant protein S, resulting in a decreased cofactor function of protein S for activated protein C. C4BP is a multimeric protein containing several identical alpha-chains and a single beta-chain (C4BPbeta), each chain being composed of short consensus repeats (SCRs). Previous studies have localized the protein S binding site to the NH2-terminal SCR (SCR-1) of C4BPbeta. To further localize the protein S binding site, we constructed chimeras containing C4BPbeta SCR-1, SCR-2, SCR-3, SCR-1+2, SCR-1+3, and SCR-2+3 fused to tissue-type plasminogen activator. Binding assays of protein S with these chimeras indicated that SCR-2 contributes to the interaction of protein S with SCR-1, since the affinity of protein S for SCR-1+2 was up to 5-fold higher compared with SCR-1 and SCR-1+3. Using an assay that measures protein S cofactor activity, we showed that cofactor activity was decreased due to binding to constructs that contain SCR-1. SCR-1+2 inhibited more potently than SCR-1 and SCR-1+3. SCR-3 had no additional effect on SCR-1, and therefore the effect of SCR-2 was specific. In conclusion, beta-chain SCR-2 contributes to the interaction of C4BP with protein S. (+info)Consumption of C4b-binding protein (C4BP) during in vivo activation of the classical complement pathway. (8/619)
C4BP has a central role in regulating the classical complement (C') pathway, but it is still uncertain whether or not it is consumed during in vivo complement activation. Attempts to demonstrate changes in C4BP plasma levels in systemic lupus erythematosus and essential mixed cryoglobulinaemia have failed, probably due to up-regulation of this protein during the inflammatory reaction. We have studied one patient with severe post-transfusion complement-mediated anaphylaxis (CMA), and 67 patients with hereditary C1 inhibitor deficiency (hereditary angioedema (HAE)). The first of these two conditions is characterized by the absence of systemic inflammatory reaction and the second by acute and chronic activation of the C' classical pathway. C4BP, C4BP-C4b complex, and soluble terminal C' complex (sC5b-9) were measured in the patients' plasmas by ELISA techniques and C3a and C4a by radioimmunoassays. In CMA, 15 min after the transfusion, there was a massive C' activation, with increases in C4a, C3a, sC5b-9, C4BP-C4b complexes and decreases in C4, C3 and C4BP. All parameters reverted to preinfusion values within 24 h. Depletion of C4 was correlated with that of C4BP. In patients with HAE, the median value of C4BP (83% range 54-165) was significantly lower (P < 0.0001) than in normal controls (99% range 70-159), with no difference between patients in remission or during acute attacks. C4BP-C4b complexes could not be detected in HAE patients. The results of this study indicate that C4BP is consumed in vivo during acute, and possibly during chronic activation of the C' classical pathway, and that this protein, after interaction with C4b, not longer circulates in plasma. (+info)Complement inactivator proteins are a group of regulatory proteins that help to control and limit the activation of the complement system, which is a part of the immune system. The complement system is a complex series of biochemical reactions that help to eliminate pathogens and damaged cells from the body. However, if not properly regulated, the complement system can also cause damage to healthy tissues and contribute to the development of various diseases.
Complement inactivator proteins work by inhibiting specific components of the complement system, preventing them from activating and causing an immune response. Some examples of complement inactivator proteins include:
1. C1 inhibitor (C1INH): This protein regulates the activation of the classical pathway of the complement system by inhibiting the C1 complex, which is a group of proteins that initiate this pathway.
2. Decay-accelerating factor (DAF or CD55): This protein regulates the activation of both the classical and alternative pathways of the complement system by accelerating the decay of the C3/C5 convertases, which are enzymes that activate the complement components C3 and C5.
3. Membrane cofactor protein (MCP or CD46): This protein regulates the activation of the alternative pathway of the complement system by serving as a cofactor for the cleavage and inactivation of C3b, a component of the C3 convertase.
4. Factor H: This protein also regulates the activation of the alternative pathway of the complement system by acting as a cofactor for the cleavage and inactivation of C3b, and by preventing the formation of the C3 convertase.
Deficiencies or dysfunction of complement inactivator proteins can lead to various diseases, including hereditary angioedema (C1INH deficiency), atypical hemolytic uremic syndrome (factor H deficiency or dysfunction), and age-related macular degeneration (complement component overactivation).
Complement C3b inactivator proteins, also known as complement regulators or decay-accelerating factor (DAF), are a group of proteins that play a crucial role in regulating the complement system. The complement system is a part of the immune system that helps to eliminate pathogens and damaged cells from the body.
The complement C3b inactivator proteins include two main types: complement receptor 1 (CR1) and decay-accelerating factor (DAF). These proteins work by regulating the formation of the membrane attack complex (MAC), a protein structure that forms pores in the cell membrane, leading to cell lysis.
Complement C3b inactivator proteins bind to C3b and C4b components of the complement system, preventing them from forming the MAC. By doing so, they help to prevent excessive activation of the complement system, which can damage healthy cells and tissues.
Deficiencies or dysfunction of complement C3b inactivator proteins have been associated with several diseases, including autoimmune disorders, inflammatory diseases, and infectious diseases. Therefore, understanding the role of these proteins in regulating the complement system is essential for developing new therapies to treat these conditions.
Complement C1 Inactivator proteins are a part of the complement system, which is a group of proteins in the blood that play a crucial role in the body's immune defense system. Specifically, Complement C1 Inactivator proteins are responsible for regulating the activation of the first component of the complement system, C1.
The complement system is activated in response to the presence of foreign substances such as bacteria or viruses in the body. The activation of C1 leads to a cascade of reactions that result in the destruction of the foreign substance. However, if this process is not properly regulated, it can lead to damage to the body's own cells and tissues.
Complement C1 Inactivator proteins help to prevent this by regulating the activation of C1. They do this by binding to and inhibiting the activity of C1, preventing it from initiating the complement cascade. A deficiency in Complement C1 Inactivator proteins can lead to a condition called hereditary angioedema, which is characterized by recurrent episodes of swelling in various parts of the body.
Complement C3 is a protein that plays a central role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Complement C3 can be activated through three different pathways: the classical pathway, the lectin pathway, and the alternative pathway. Once activated, it breaks down into two fragments, C3a and C3b.
C3a is an anaphylatoxin that helps to recruit immune cells to the site of infection or injury, while C3b plays a role in opsonization, which is the process of coating pathogens or damaged cells with proteins to make them more recognizable to the immune system. Additionally, C3b can also activate the membrane attack complex (MAC), which forms a pore in the membrane of target cells leading to their lysis or destruction.
In summary, Complement C3 is an important protein in the complement system that helps to identify and eliminate pathogens and damaged cells from the body through various mechanisms.
Complement activation is the process by which the complement system, a part of the immune system, is activated to help eliminate pathogens and damaged cells from the body. The complement system consists of a group of proteins that work together to recognize and destroy foreign substances.
Activation of the complement system can occur through three different pathways: the classical pathway, the lectin pathway, and the alternative pathway. Each pathway involves a series of proteolytic reactions that ultimately result in the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, leading to its lysis and removal.
The classical pathway is typically activated by the binding of antibodies to antigens on the surface of a pathogen or damaged cell. The lectin pathway is activated by the recognition of specific carbohydrate structures on the surface of microorganisms. The alternative pathway can be spontaneously activated and serves as an amplification loop for both the classical and lectin pathways.
Complement activation plays a crucial role in the immune response, but uncontrolled or excessive activation can also lead to tissue damage and inflammation. Dysregulation of complement activation has been implicated in various diseases, including autoimmune disorders, inflammatory conditions, and neurodegenerative diseases.
The complement system is a group of proteins found in the blood and on the surface of cells that when activated, work together to help eliminate pathogens such as bacteria, viruses, and fungi from the body. The proteins are normally inactive in the bloodstream. When they encounter an invading microorganism or foreign substance, a series of reactions take place leading to the activation of the complement system. Activation results in the production of effector molecules that can punch holes in the cell membranes of pathogens, recruit and activate immune cells, and help remove debris and dead cells from the body.
There are three main pathways that can lead to complement activation: the classical pathway, the lectin pathway, and the alternative pathway. Each pathway involves a series of proteins that work together in a cascade-like manner to amplify the response and generate effector molecules. The three main effector molecules produced by the complement system are C3b, C4b, and C5b. These molecules can bind to the surface of pathogens, marking them for destruction by other immune cells.
Complement proteins also play a role in the regulation of the immune response. They help to prevent excessive activation of the complement system, which could damage host tissues. Dysregulation of the complement system has been implicated in a number of diseases, including autoimmune disorders and inflammatory conditions.
In summary, Complement System Proteins are a group of proteins that play a crucial role in the immune response by helping to eliminate pathogens and regulate the immune response. They can be activated through three different pathways, leading to the production of effector molecules that mark pathogens for destruction. Dysregulation of the complement system has been linked to various diseases.
Complement C4 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Complement C4 is involved in the early stages of the complement activation cascade, where it helps to identify and tag foreign or abnormal cells for destruction by other components of the immune system.
Specifically, Complement C4 can be cleaved into two smaller proteins, C4a and C4b, during the complement activation process. C4b then binds to the surface of the target cell and helps to initiate the formation of the membrane attack complex (MAC), which creates a pore in the cell membrane and leads to lysis or destruction of the target cell.
Deficiencies or mutations in the Complement C4 gene can lead to various immune disorders, including certain forms of autoimmune diseases and susceptibility to certain infections.
Complement C5 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. The complement system is a complex series of biochemical reactions that help to identify and destroy foreign substances, such as bacteria and viruses.
Complement C5 is one of several proteins in the complement system that are activated in a cascading manner in response to an activating event, such as the binding of an antibody to a pathogen. Once activated, Complement C5 can be cleaved into two smaller proteins, C5a and C5b.
C5a is a powerful anaphylatoxin, which means it can cause the release of histamine from mast cells and basophils, leading to inflammation and increased vascular permeability. It also acts as a chemoattractant, drawing immune cells to the site of infection or injury.
C5b, on the other hand, plays a role in the formation of the membrane attack complex (MAC), which is a protein structure that can punch holes in the membranes of pathogens, leading to their lysis and destruction.
Overall, Complement C5 is an important component of the immune system's response to infection and injury, helping to eliminate pathogens and damaged cells from the body.
Complement C3b is a protein fragment that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. C3b is generated during the activation of the complement system, particularly via the classical, lectin, and alternative pathways.
Once formed, C3b can bind covalently to the surface of microbes or other target particles, marking them for destruction by other components of the immune system. Additionally, C3b can interact with other proteins in the complement system to generate the membrane attack complex (MAC), which forms pores in the membranes of targeted cells, leading to their lysis and removal.
In summary, Complement C3b is a vital protein fragment involved in the recognition, tagging, and elimination of pathogens and damaged cells during the immune response.
The alternative complement pathway is one of the three initiating pathways of the complement system, which is a part of the innate immune system that helps to clear pathogens and damaged cells from the body. The other two pathways are the classical and lectin pathways.
The alternative pathway is continuously activated at a low level, even in the absence of infection or injury, through the spontaneous cleavage of complement component C3 into C3a and C3b by the protease factor D in the presence of magnesium ions. The generated C3b can then bind covalently to nearby surfaces, including pathogens and host cells.
On self-surfaces, regulatory proteins like decay-accelerating factor (DAF) or complement receptor 1 (CR1) help to prevent the formation of the alternative pathway convertase and thus further activation of the complement system. However, on foreign surfaces, the C3b can recruit more complement components, forming a complex called the alternative pathway convertase (C3bBb), which cleaves additional C3 molecules into C3a and C3b.
The generated C3b can then bind to the surface and participate in the formation of the membrane attack complex (MAC), leading to the lysis of the target cell. The alternative pathway plays a crucial role in the defense against gram-negative bacteria, fungi, and parasites, as well as in the clearance of immune complexes and apoptotic cells. Dysregulation of the alternative complement pathway has been implicated in several diseases, including autoimmune disorders and atypical hemolytic uremic syndrome (aHUS).
Complement receptors are proteins found on the surface of various cells in the human body, including immune cells and some non-immune cells. They play a crucial role in the complement system, which is a part of the innate immune response that helps to eliminate pathogens and damaged cells from the body. Complement receptors bind to complement proteins or fragments that are generated during the activation of the complement system. This binding triggers various intracellular signaling events that can lead to diverse cellular responses, such as phagocytosis, inflammation, and immune regulation.
There are several types of complement receptors, including:
1. CR1 (CD35): A receptor found on erythrocytes, B cells, neutrophils, monocytes, macrophages, and glomerular podocytes. It functions in the clearance of immune complexes and regulates complement activation.
2. CR2 (CD21): Expressed mainly on B cells and follicular dendritic cells. It facilitates antigen presentation, B-cell activation, and immune regulation.
3. CR3 (CD11b/CD18, Mac-1): Present on neutrophils, monocytes, macrophages, and some T cells. It mediates cell adhesion, phagocytosis, and intracellular signaling.
4. CR4 (CD11c/CD18, p150,95): Expressed on neutrophils, monocytes, macrophages, and dendritic cells. It is involved in cell adhesion, phagocytosis, and intracellular signaling.
5. C5aR (CD88): Found on various immune cells, including neutrophils, monocytes, macrophages, mast cells, eosinophils, and dendritic cells. It binds to the complement protein C5a and mediates chemotaxis, degranulation, and inflammation.
6. C5L2 (GPR77): Present on various cell types, including immune cells. Its function is not well understood but may involve regulating C5a-mediated responses or acting as a receptor for other ligands.
These receptors play crucial roles in the immune response and inflammation by mediating various functions such as chemotaxis, phagocytosis, cell adhesion, and intracellular signaling. Dysregulation of these receptors has been implicated in several diseases, including autoimmune disorders, infections, and cancer.
Complement C2 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C2 is a component of the classical complement pathway, which is activated by the binding of antibodies to antigens on the surface of foreign particles or cells.
When the classical pathway is activated, C2 is cleaved into two fragments: C2a and C2b. C2a then binds to C4b to form the C3 convertase (C4b2a), which cleaves C3 into C3a and C3b. C3b can then go on to form the membrane attack complex, which creates a pore in the membrane of the target cell, leading to its lysis.
In summary, Complement C2 is a protein that helps to activate the complement system and destroy foreign particles or cells through the formation of the C3 convertase and the membrane attack complex.
The "Classical Complement Pathway" is one of the three pathways that make up the complement system, which is a part of the immune system in humans and other animals. The complement system helps to enhance the ability of antibodies and phagocytic cells to clear pathogens from the body.
The Classical Complement Pathway is initiated by the binding of the first component of the complement system, C1, to an activator surface, such as an antigen-antibody complex. Activation of C1 results in the sequential activation of other components of the complement system, including C4 and C2, which form the C3 convertase (C4b2a). The C3 convertase cleaves the third component of the complement system, C3, into C3a and C3b. C3b then binds to the activator surface and forms a complex with other components of the complement system, leading to the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, causing its lysis.
The Classical Complement Pathway plays an important role in the immune response to pathogens and can also contribute to inflammation and tissue damage in certain diseases, such as autoimmune disorders and allergies.
Complement Factor B is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, Factor B is a component of the alternative pathway of the complement system, which provides a rapid and amplified response to microbial surfaces.
Factor B is cleaved by another protease called Factor D into two fragments, Ba and Bb. The formation of the C3 convertase (C3bBb) is essential for the activation of the alternative pathway. This complex can cleave and activate more C3 molecules, leading to a cascade of reactions that result in the formation of the membrane attack complex (MAC), which forms pores in the membranes of target cells, causing their lysis and elimination.
Deficiencies or mutations in Complement Factor B can lead to various complement-mediated diseases, such as atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration (AMD).
Properdin is defined as a positive regulatory protein in the complement system, which is a part of the immune system. It plays a crucial role in the alternative pathway of complement activation. Properdin stabilizes the C3 convertase (C3bBb), preventing its decay and increasing the efficiency of the alternative pathway. This results in the production of the membrane attack complex, which leads to the lysis of foreign cells or pathogens. Deficiencies in properdin can lead to an increased susceptibility to bacterial infections.
Complement C1q is a protein that is part of the complement system, which is a group of proteins in the blood that help to eliminate pathogens and damaged cells from the body. C1q is the first component of the classical complement pathway, which is activated by the binding of C1q to antibodies that are attached to the surface of a pathogen or damaged cell.
C1q is composed of six identical polypeptide chains, each containing a collagen-like region and a globular head region. The globular heads can bind to various structures, including the Fc regions of certain antibodies, immune complexes, and some types of cells. When C1q binds to an activating surface, it triggers a series of proteolytic reactions that lead to the activation of other complement components and the formation of the membrane attack complex (MAC), which can punch holes in the membranes of pathogens or damaged cells, leading to their destruction.
In addition to its role in the immune system, C1q has also been found to have roles in various physiological processes, including tissue remodeling, angiogenesis, and the clearance of apoptotic cells. Dysregulation of the complement system, including abnormalities in C1q function, has been implicated in a variety of diseases, including autoimmune disorders, inflammatory diseases, and neurodegenerative conditions.
Complement C9 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C9 is one of the components of the membrane attack complex (MAC), which is a protein structure that forms pores in the membranes of target cells, leading to their lysis or destruction.
When activated, C9 polymerizes and inserts itself into the cell membrane, forming a transmembrane pore that disrupts the membrane's integrity and causes the cell to lyse. This process is an essential part of the complement system's ability to destroy pathogens and clear damaged cells from the body.
Defects in the C9 gene can lead to a rare genetic disorder called complement component 9 deficiency, which is characterized by recurrent bacterial infections and immune complex-mediated diseases. Additionally, mutations in the C9 gene have been associated with an increased risk of age-related macular degeneration (AMD), a leading cause of blindness in older adults.
Complement Factor H is a protein involved in the regulation of the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, Complement Factor H helps to regulate the activation and deactivation of the complement component C3b, preventing excessive or unwanted activation of the complement system and protecting host tissues from damage.
Complement Factor H is a crucial protein in maintaining the balance between the protective effects of the complement system and the potential for harm to the body's own cells and tissues. Deficiencies or mutations in Complement Factor H have been associated with several diseases, including age-related macular degeneration (AMD), atypical hemolytic uremic syndrome (aHUS), and C3 glomerulopathy.
Complement activating enzymes are proteins that play a crucial role in the activation of the complement system, which is a part of the immune system. The complement system is a complex series of biochemical reactions that help to eliminate pathogens and damaged cells from the body.
There are several types of complement activating enzymes, including:
1. Classical pathway activators: These include the C1, C4, and C2 components of the complement system. When activated, they trigger a series of reactions that lead to the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, leading to its lysis.
2. Alternative pathway activators: These include factors B, D, and P. They are constantly active at low levels and can be activated by surfaces that are not normally found in the body, such as bacterial cell walls. Once activated, they also trigger the formation of the MAC.
3. Lectin pathway activators: These include mannose-binding lectin (MBL) and ficolins. They bind to carbohydrates on the surface of microbes and activate the complement system through the MBL-associated serine proteases (MASPs).
Overall, complement activating enzymes play a critical role in the immune response by helping to identify and eliminate pathogens and damaged cells from the body.
The Complement Membrane Attack Complex (MAC), also known as the Terminal Complement Complex (TCC), is a protein structure that forms in the final stages of the complement system's immune response. The complement system is a part of the innate immune system that helps to eliminate pathogens and damaged cells from the body.
The MAC is composed of several proteins, including C5b, C6, C7, C8, and multiple subunits of C9, which assemble on the surface of target cells. The formation of the MAC creates a pore-like structure in the cell membrane, leading to disruption of the membrane's integrity and ultimately causing cell lysis or damage.
The MAC plays an important role in the immune response by helping to eliminate pathogens that have evaded other immune defenses. However, uncontrolled activation of the complement system and formation of the MAC can also contribute to tissue damage and inflammation in various diseases, such as autoimmune disorders, age-related macular degeneration, and ischemia-reperfusion injury.
Complement C3-C5 convertases are proteins that play a crucial role in the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by marking them for destruction and attracting immune cells to the site of infection or injury.
The C3-C5 convertases are formed during the activation of the complement component 3 (C3) protein, which is a central player in the complement system. The formation of the C3-C5 convertase involves two main steps:
1. C3 convertase formation: In this step, a complex of proteins called the C3 convertase is formed by the cleavage of C3 into C3a and C3b fragments. This complex can then cleave additional C3 molecules into C3a and C3b fragments, amplifying the complement response.
2. C5 convertase formation: In this step, the C3b fragment from the C3 convertase binds to another protein called C4b2a, forming a new complex called the C5 convertase. The C5 convertase can then cleave the C5 protein into C5a and C5b fragments.
The C5b fragment goes on to form the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, leading to its lysis or destruction. The C3a and C5a fragments are small proteins called anaphylatoxins that can cause inflammation and attract immune cells to the site of infection or injury.
Overall, the formation of Complement C3-C5 convertases is a critical step in the activation of the complement system and plays a key role in the body's defense against pathogens and damaged cells.
Complement inactivating agents are substances or drugs that inhibit the complement system, which is a part of the immune system responsible for the recognition and elimination of foreign substances and microorganisms. The complement system consists of a group of proteins that work together to help eliminate pathogens from the body.
Complement inactivating agents are used in medical settings to prevent or treat various conditions associated with excessive or unwanted activation of the complement system, such as inflammation, autoimmune diseases, and transplant rejection. These agents can inhibit different components of the complement pathway, including C1 esterase inhibitors, C3 convertase inhibitors, and C5a receptor antagonists.
Examples of complement inactivating agents include eculizumab, ravulizumab, and Alexion's Ultomiris, which are monoclonal antibodies that target C5, a protein involved in the final steps of the complement pathway. These drugs have been approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), and other complement-mediated diseases.
Other complement inactivating agents include C1 esterase inhibitors, such as Berinert and Ruconest, which are used to treat hereditary angioedema (HAE). These drugs work by inhibiting the activation of the classical pathway of the complement system, thereby preventing the release of inflammatory mediators that can cause swelling and pain.
Overall, complement inactivating agents play an important role in the treatment of various complement-mediated diseases, helping to reduce inflammation, prevent tissue damage, and improve patient outcomes.
Complement C3a is a protein fragment that is generated during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by marking them for destruction and attracting immune cells to the site of infection or injury.
C3a is produced when the third component of the complement system (C3) is cleaved into two smaller fragments, C3a and C3b, during the complement activation cascade. C3a is a potent anaphylatoxin, which means it can cause the release of histamine and other mediators from mast cells and basophils, leading to inflammation, increased vascular permeability, and smooth muscle contraction.
C3a also has chemotactic properties, meaning it can attract immune cells such as neutrophils and monocytes to the site of complement activation. Additionally, C3a can modulate the activity of various immune cells, including dendritic cells, T cells, and B cells, and play a role in the regulation of the adaptive immune response.
It's important to note that while C3a has important functions in the immune response, uncontrolled or excessive activation of the complement system can lead to tissue damage and inflammation, contributing to the pathogenesis of various diseases such as autoimmune disorders, inflammatory diseases, and allergies.
Complement C5a is a protein fragment that is generated during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by tagging them for destruction and attracting immune cells to the site of infection or injury.
C5a is formed when the fifth component of the complement system (C5) is cleaved into two smaller fragments, C5a and C5b, during the complement activation cascade. C5a is a potent pro-inflammatory mediator that can attract and activate various immune cells, such as neutrophils, monocytes, and eosinophils, to the site of infection or injury. It can also increase vascular permeability, promote the release of histamine, and induce the production of reactive oxygen species, all of which contribute to the inflammatory response.
However, excessive or uncontrolled activation of the complement system and generation of C5a can lead to tissue damage and inflammation, contributing to the pathogenesis of various diseases, such as sepsis, acute respiratory distress syndrome (ARDS), and autoimmune disorders. Therefore, targeting C5a or its receptors has been explored as a potential therapeutic strategy for these conditions.
Complement C6 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C6 is a component of the membrane attack complex (MAC), which is a group of proteins that work together to form a pore in the membrane of target cells, leading to their lysis or destruction.
The complement system is activated through several different pathways, including the classical pathway, the lectin pathway, and the alternative pathway. Once activated, these pathways converge at the level of C3, which is cleaved into C3a and C3b fragments. C3b can then bind to the surface of target cells and initiate the formation of the MAC.
C6 is one of several proteins that are required for the formation of the MAC. When C6 binds to C7, it undergoes a conformational change that allows it to interact with C8 and form a stable complex. This complex then recruits additional C9 molecules, which polymerize to form the pore in the target cell membrane.
Deficiencies in complement components, including C6, can lead to increased susceptibility to certain types of infections, as well as autoimmune disorders and other medical conditions.
Complement receptor 3b (CR3b or CD11b/CD18) is not a medical definition itself, but I can provide you with the relevant information regarding this term.
Complement receptor 3 (CR3) is a heterodimeric receptor consisting of two subunits, CD11b (also known as Mac-1 or CR3 alpha) and CD18 (also known as beta2 integrin). There are two forms of the CD11b/CD18 heterodimer: CR3a (CD11b/CD18) and CR3b (CD11b/CD18'). The difference between these two forms lies in the conformation of the CD11b subunit.
Complement receptor 3b (CR3b or CD11b/CD18') is a less common form of the CR3 receptor, which is primarily expressed on myeloid cells such as monocytes, macrophages, and neutrophils. CR3b has a higher affinity for complement component C3b and its fragments iC3b and C3dg compared to CR3a.
CR3b plays a role in various immune functions, including:
1. Phagocytosis: Binding of C3b or its fragments to CR3b facilitates the recognition and uptake of opsonized pathogens by phagocytes.
2. Adhesion: The integrin component of CR3b mediates cell-cell and cell-matrix interactions, contributing to leukocyte migration and recruitment to sites of inflammation or infection.
3. Intracellular signaling: Activation of CR3b can lead to intracellular signaling events that modulate immune responses, such as the release of pro-inflammatory cytokines and reactive oxygen species.
In summary, Complement receptor 3b (CR3b or CD11b/CD18') is a less common form of CR3 primarily expressed on myeloid cells that binds complement component C3b and its fragments with high affinity, mediating phagocytosis, adhesion, and intracellular signaling.
Complement C1 is a protein complex that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. The complement system consists of a group of proteins that work together to destroy microbes and remove debris.
Complement C1 is composed of three subunits: C1q, C1r, and C1s. When activated, C1q binds to the surface of a pathogen or damaged cell, leading to the activation of C1r and C1s. Activated C1r then cleaves and activates C1s, which in turn cleaves and activates other complement components, ultimately resulting in the formation of the membrane attack complex (MAC), a protein structure that forms a pore in the membrane of the target cell, leading to its lysis and destruction.
Defects in the complement component C1 can lead to immune disorders, such as hereditary angioedema, which is characterized by recurrent episodes of swelling in various parts of the body.
Complement C4b is a protein fragment that is formed during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by tagging them for destruction and attracting immune cells to the site of infection or injury.
C4b is generated when the C4 protein is cleaved into two smaller fragments, C4a and C4b, during the activation of the classical or lectin pathways of the complement system. C4b then binds covalently to the surface of the target cell or pathogen, forming a complex with other complement proteins that can create a membrane attack complex (MAC) and cause cell lysis.
C4b can also act as an opsonin, coating the surface of the target cell or pathogen and making it easier for immune cells to recognize and phagocytose them. Additionally, C4b can activate the alternative pathway of the complement system, leading to further amplification of the complement response.
Anaphylatoxins are a group of small protein molecules that are released during an immune response, specifically as a result of the activation of the complement system. The term "anaphylatoxin" comes from their ability to induce anaphylaxis, a severe and rapid allergic reaction. There are three main anaphylatoxins, known as C3a, C4a, and C5a, which are derived from the cleavage of complement components C3, C4, and C5, respectively.
Anaphylatoxins play a crucial role in the immune response by attracting and activating various immune cells, such as neutrophils, eosinophils, and mast cells, to the site of infection or injury. They also increase vascular permeability, causing fluid to leak out of blood vessels and leading to tissue swelling. Additionally, anaphylatoxins can induce smooth muscle contraction, which can result in bronchoconstriction and hypotension.
While anaphylatoxins are important for the immune response, they can also contribute to the pathogenesis of various inflammatory diseases, such as asthma, arthritis, and sepsis. Therefore, therapies that target the complement system and anaphylatoxin production have been developed and are being investigated as potential treatments for these conditions.
Complement C3d is a protein fragment that is formed during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens such as bacteria and viruses from the body by tagging them for destruction and attracting immune cells to the site of infection.
C3d is a cleavage product of complement component C3, which is one of the central proteins in the complement system. When C3 is activated, it is cleaved into two fragments: C3a and C3b. C3b can then be further cleaved into C3d and C3c.
C3d plays a role in the activation of the immune system by helping to link the complement system with the adaptive immune response. It does this by binding to receptors on B cells, which are a type of white blood cell that produces antibodies. This interaction can help to stimulate the production of antibodies and enhance the immune response to pathogens.
C3d has also been implicated in the development of certain autoimmune diseases, as it can contribute to the formation of immune complexes that can cause tissue damage.
Complement fixation tests are a type of laboratory test used in immunology and serology to detect the presence of antibodies in a patient's serum. These tests are based on the principle of complement activation, which is a part of the immune response. The complement system consists of a group of proteins that work together to help eliminate pathogens from the body.
In a complement fixation test, the patient's serum is mixed with a known antigen and complement proteins. If the patient has antibodies against the antigen, they will bind to it and activate the complement system. This results in the consumption or "fixation" of the complement proteins, which are no longer available to participate in a secondary reaction.
A second step involves adding a fresh source of complement proteins and a dye-labeled antibody that recognizes a specific component of the complement system. If complement was fixed during the first step, it will not be available for this secondary reaction, and the dye-labeled antibody will remain unbound. Conversely, if no antibodies were present in the patient's serum, the complement proteins would still be available for the second reaction, leading to the binding of the dye-labeled antibody.
The mixture is then examined under a microscope or using a spectrophotometer to determine whether the dye-labeled antibody has bound. If it has not, this indicates that the patient's serum contains antibodies specific to the antigen used in the test, and a positive result is recorded.
Complement fixation tests have been widely used for the diagnosis of various infectious diseases, such as syphilis, measles, and influenza. However, they have largely been replaced by more modern serological techniques, like enzyme-linked immunosorbent assays (ELISAs) and nucleic acid amplification tests (NAATs), due to their increased sensitivity, specificity, and ease of use.
Complement C7 is a protein that plays a role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, C7 is a component of the membrane attack complex (MAC), which is a group of proteins that forms a pore in the membrane of target cells, leading to their lysis or destruction.
C7 is activated when it binds to the C5b-7 complex, which is formed by the cleavage of C5 and C6 by the C5 convertase. Once bound to the C5b-7 complex, C7 undergoes a conformational change that allows it to insert into the target cell membrane. This forms the basis for the formation of the MAC and subsequent lysis of the target cell.
Deficiencies in complement components, including C7, can lead to increased susceptibility to certain infections and autoimmune disorders. Additionally, abnormal regulation of the complement system has been implicated in a variety of diseases, including inflammatory and degenerative conditions.
Complement C8 is a protein component of the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C8 is a part of the membrane attack complex (MAC), which forms a pore in the membrane of target cells, leading to their lysis or destruction.
C8 is composed of three subunits: alpha, beta, and gamma. It is activated when it binds to the complement component C5b67 complex on the surface of a target cell. Once activated, C8 undergoes a conformational change that allows it to insert into the target cell membrane and form a pore, which disrupts the cell's membrane integrity and can lead to its death.
Deficiencies in complement components, including C8, can make individuals more susceptible to certain infections and autoimmune diseases. Additionally, mutations in the genes encoding complement proteins have been associated with various inherited disorders, such as atypical hemolytic uremic syndrome (aHUS), which is characterized by thrombotic microangiopathy and kidney failure.
Complement C3c is a protein component of the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Complement C3c is formed when the third component of the complement system (C3) is cleaved into two smaller proteins, C3a and C3b, during the complement activation process.
C3b can then be further cleaved into C3c and C3dg. C3c is a stable fragment that remains in the circulation and can be measured in blood tests as a marker of complement activation. It plays a role in the opsonization of pathogens, which means it coats them to make them more recognizable to immune cells, and helps to initiate the membrane attack complex (MAC), which forms a pore in the cell membrane of pathogens leading to their lysis or destruction.
Abnormal levels of C3c may indicate an underlying inflammatory or immune-mediated condition, such as infection, autoimmune disease, or cancer.
Hemolysis is the destruction or breakdown of red blood cells, resulting in the release of hemoglobin into the surrounding fluid (plasma). This process can occur due to various reasons such as chemical agents, infections, autoimmune disorders, mechanical trauma, or genetic abnormalities. Hemolysis may lead to anemia and jaundice, among other complications. It is essential to monitor hemolysis levels in patients undergoing medical treatments that might cause this condition.
Complement receptor 3d (CR3d or CD11b/CD18) is not a medical definition in itself, but rather a specific type of integrin receptor that plays a crucial role in the immune system. Here's a breakdown of the components:
1. Complement Receptors: These are proteins found on the surface of various cells, including white blood cells (leukocytes), that recognize and bind to complement components, which are proteins involved in the immune response. The binding of complement components to their receptors helps facilitate communication between cells, enhances phagocytosis (the process by which certain cells engulf and destroy foreign particles or microorganisms), and contributes to the inflammatory response.
2. CR3 (Complement Receptor 3): Complement Receptor 3 is a heterodimeric receptor composed of two subunits, CD11b (also known as integrin alpha M) and CD18 (also known as integrin beta 2). Together, they form the integrin Mac-1 or αMβ2.
3. CR3d (CD11b/CD18): CR3d specifically refers to the CD11b subunit of the Complement Receptor 3 heterodimer. The CD11b subunit is responsible for recognizing and binding to complement component C3b, iC3b, and C4b fragments, as well as other ligands such as fibrinogen, ICAM-1 (Intercellular Adhesion Molecule 1), and factor X.
In summary, Complement Receptor 3d (CR3d or CD11b/CD18) is a type of integrin receptor found on the surface of various immune cells that recognizes and binds to complement components C3b, iC3b, and C4b fragments, as well as other ligands. This binding facilitates communication between cells, enhances phagocytosis, and contributes to the inflammatory response.
A Complement Hemolytic Activity Assay is a laboratory test used to measure the functionality and activity level of the complement system, which is a part of the immune system. The complement system is a group of proteins that work together to help eliminate pathogens from the body.
The assay measures the ability of the complement system to lyse (break open) red blood cells. This is done by mixing the patient's serum (the liquid portion of the blood) with antibody-coated red blood cells and incubating them together. The complement proteins in the serum will then bind to the antibodies on the red blood cells and cause them to lyse.
The degree of hemolysis (red blood cell lysis) is directly proportional to the activity level of the complement system. By measuring the amount of hemolysis, the assay can determine whether the complement system is functioning properly and at what level of activity.
This test is often used to diagnose or monitor complement-mediated diseases such as autoimmune disorders, infections, and some types of cancer. It may also be used to evaluate the effectiveness of treatments that target the complement system.
Complement C4a is a protein fragment or cleavage product generated during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells by marking them for destruction and direct lysis. Complement component 4 (C4) is one of the key proteins in this cascade, and it gets cleaved into C4a and C4b during the activation process.
C4a is a small anaphylatoxin with a molecular weight of approximately 9 kDa. It has chemotactic properties, meaning it can attract immune cells like neutrophils to the site of complement activation. Additionally, C4a can induce histamine release from mast cells and basophils, contributing to local inflammation. However, its precise physiological role in the immune response is not entirely clear, and dysregulation of C4a production has been implicated in several pathological conditions, such as autoimmune diseases and allergies.
Lysine carboxypeptidase is not a widely recognized or used medical term. However, in biochemistry, carboxypeptidases are enzymes that cleave peptide bonds at the carboxyl-terminal end of a protein or peptide. If there is a specific enzyme named "lysine carboxypeptidase," it would be an enzyme that selectively removes lysine residues from the carboxyl terminus of a protein or peptide.
There are several enzymes that can act as carboxypeptidases, and some of them have specificities for certain amino acids, such as arginine or lysine. These enzymes play important roles in various biological processes, including protein degradation, processing, and regulation.
It's worth noting that the term "lysine carboxypeptidase" may refer to different enzymes depending on the context, such as bacterial or mammalian enzymes, and they may have different properties and functions.
Complement Factor D is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, Factor D is a serine protease that is involved in the alternative pathway of the complement system.
In this pathway, Factor D helps to cleave another protein called Factor B, which then activates a complex called the C3 convertase. The C3 convertase cleaves complement component 3 (C3) into C3a and C3b, leading to the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, causing its lysis and removal from the body.
Deficiencies or mutations in Complement Factor D can lead to an impaired alternative pathway and increased susceptibility to certain infections, particularly those caused by Neisseria bacteria. Additionally, abnormal regulation of the complement system has been implicated in a variety of diseases, including autoimmune disorders, inflammatory conditions, and neurodegenerative diseases.
Beta-globulins are a group of proteins found in the beta region of a serum protein electrophoresis, which is a laboratory test used to separate and identify different types of proteins in the blood. This group includes several important proteins such as:
1. Beta-lipoproteins: These are responsible for transporting fat molecules, including cholesterol, throughout the body.
2. Transferrin: A protein that binds and transports iron in the blood.
3. Complement components: These proteins play a crucial role in the immune system's response to infection and inflammation.
4. Beta-2 microglobulin: A protein involved in the functioning of the immune system, elevated levels of which can be found in various conditions such as kidney disease and autoimmune disorders.
5. Hemopexin: A protein that binds and transports heme (a component of hemoglobin) in the blood.
It is important to note that any significant increase or decrease in beta-globulins can indicate an underlying medical condition, such as liver disease, kidney disease, or an autoimmune disorder. Therefore, abnormal results should be further evaluated by a healthcare professional for proper diagnosis and treatment.
Complement Factor I is a protein involved in the regulation of the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, Complement Factor I is a serine protease that regulates the complement component C3b by cleaving it into inactive fragments, thereby preventing the excessive activation of the complement system and protecting host tissues from damage.
Complement Factor I functions in conjunction with other regulatory proteins, such as complement receptor 1 (CR1) and membrane cofactor protein (MCP), to control the activity of the complement system at various stages. Deficiencies or mutations in Complement Factor I have been associated with several diseases, including atypical hemolytic uremic syndrome (aHUS), age-related macular degeneration (AMD), and systemic lupus erythematosus (SLE).
Complement C4b-binding protein (C4bp) is a regulatory protein in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. C4bp regulates the complement system by binding to and inhibiting the activity of C4b, an activated component of the classical and lectin pathways of the complement system. By doing so, C4bp helps to prevent excessive or inappropriate activation of the complement system, which could otherwise lead to tissue damage and inflammation.
C4bp is a complex protein that consists of several subunits, including a central α-chain and multiple β-chains. It is produced by liver cells and can also be found on the surface of some cells in the body. Mutations in the genes encoding C4bp have been associated with certain immune disorders, such as systemic lupus erythematosus (SLE) and atypical hemolytic uremic syndrome (aHUS).
Complement C1s is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, C1s is a component of the first protein complex in the classical complement pathway, called C1.
C1 is composed of three subunits: C1q, C1r, and C1s. When C1 encounters an activating surface, such as an antibody-antigen complex or certain types of viruses and bacteria, it undergoes a conformational change that allows C1r to cleave and activate C1s. Activated C1s then goes on to cleave and activate other components in the complement pathway, leading to the generation of the membrane attack complex (MAC) and subsequent lysis of the target cell.
Deficiencies or mutations in the genes encoding complement proteins, including C1s, can lead to various immune disorders and increased susceptibility to infections.
Immunoelectrophoresis (IEP) is a laboratory technique used in the field of clinical pathology and immunology. It is a method for separating and identifying proteins, particularly immunoglobulins or antibodies, in a sample. This technique combines the principles of electrophoresis, which separates proteins based on their electric charge and size, with immunological reactions, which detect specific proteins using antigen-antibody interactions.
In IEP, a protein sample is first separated by electrophoresis in an agarose or agar gel matrix on a glass slide or in a test tube. After separation, an antibody specific to the protein of interest is layered on top of the gel and allowed to diffuse towards the separated proteins. This creates a reaction between the antigen (protein) and the antibody, forming a visible precipitate at the point where they meet. The precipitate line's position and intensity can then be analyzed to identify and quantify the protein of interest.
Immunoelectrophoresis is particularly useful in diagnosing various medical conditions, such as immunodeficiency disorders, monoclonal gammopathies (like multiple myeloma), and other plasma cell dyscrasias. It can help detect abnormal protein patterns, quantify specific immunoglobulins, and identify the presence of M-proteins or Bence Jones proteins, which are indicative of monoclonal gammopathies.
Cytochrome P-450 CYP2B1 is a specific isoform of the cytochrome P-450 enzyme system, which is involved in the metabolism of drugs and other xenobiotics in the liver. This particular isoenzyme is primarily found in rats and is responsible for the metabolism of a variety of substrates, including certain drugs, steroids, and environmental toxins.
The cytochrome P-450 system is a group of enzymes located in the endoplasmic reticulum of cells, particularly in the liver. These enzymes play a crucial role in the metabolism of various substances, including drugs, hormones, and toxins. They work by catalyzing oxidation-reduction reactions that convert lipophilic compounds into more hydrophilic ones, which can then be excreted from the body.
CYP2B1 is one of many isoforms of cytochrome P-450, and it has a preference for certain types of substrates. It is involved in the metabolism of drugs such as cyclophosphamide, ifosfamide, and methadone, as well as steroids like progesterone and environmental toxins like pentachlorophenol.
It's important to note that while CYP2B1 is an essential enzyme in rats, its human counterpart, CYP2B6, plays a similar role in drug metabolism in humans. Understanding the function and regulation of these enzymes can help in predicting drug interactions, designing new drugs, and tailoring therapies to individual patients based on their genetic makeup.
Chloromercurinitrophenols are organic compounds that contain a mercury atom, a chlorine atom, a nitro group (-NO2), and a phenol group (-C6H5OH). They have the general formula C6H4ClHgNO2. These compounds were once used in medicine as antiseptics and preservatives, but their use has been largely discontinued due to their toxicity and environmental persistence.
An antigen-antibody complex is a type of immune complex that forms when an antibody binds to a specific antigen. An antigen is any substance that triggers an immune response, while an antibody is a protein produced by the immune system to neutralize or destroy foreign substances like antigens.
When an antibody binds to an antigen, it forms a complex that can be either soluble or insoluble. Soluble complexes are formed when the antigen is small and can move freely through the bloodstream. Insoluble complexes, on the other hand, are formed when the antigen is too large to move freely, such as when it is part of a bacterium or virus.
The formation of antigen-antibody complexes plays an important role in the immune response. Once formed, these complexes can be recognized and cleared by other components of the immune system, such as phagocytes, which help to prevent further damage to the body. However, in some cases, the formation of large numbers of antigen-antibody complexes can lead to inflammation and tissue damage, contributing to the development of certain autoimmune diseases.
Angioedema is a medical condition characterized by rapid swelling of the skin, mucous membranes, and submucosal tissues. The swelling typically occurs in the face, lips, tongue, larynx, and extremities, and can also affect the gastrointestinal tract. Angioedema can be caused by a variety of factors, including allergic reactions, hereditary genetic mutations, and certain medications.
In medical terms, angioedema is defined as a self-limiting episode of localized edema in the deep dermis, subcutaneous tissue, or mucous membranes, characterized by well-circumscribed, nonpitting, nondependent swelling. The swelling can occur suddenly and may persist for up to 72 hours. In severe cases, angioedema can cause airway obstruction and be life-threatening if not treated promptly.
Angioedema can be classified into two main types: allergic or non-allergic. Allergic angioedema is caused by an immune response to an allergen, such as food, medication, or insect venom. Non-allergic angioedema can be further divided into several subtypes, including hereditary angioedema (HA), acquired angioedema (AAE), and drug-induced angioedema.
Hereditary angioedema is a rare genetic disorder caused by mutations in the C1 inhibitor gene, leading to uncontrolled activation of the complement system and increased production of bradykinin, a potent vasodilator. Acquired angioedema is similar to hereditary angioedema but occurs later in life and is associated with underlying medical conditions such as lymphoproliferative disorders or autoimmune diseases. Drug-induced angioedema can be caused by a variety of medications, including ACE inhibitors, angiotensin receptor blockers (ARBs), and nonsteroidal anti-inflammatory drugs (NSAIDs).
The diagnosis of angioedema is typically based on clinical presentation, medical history, and laboratory tests. Treatment depends on the underlying cause of the condition but may include antihistamines, corticosteroids, epinephrine, and medications that target the complement system or bradykinin pathway. In severe cases, hospitalization and intensive care may be necessary to manage airway obstruction and other complications.
In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."
1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.
2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.
3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.
4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).
Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.
Complement C1r is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, C1r is one of the three proteins that make up the C1 complex, which is the first component of the classical complement pathway.
The C1 complex is composed of C1q, C1r, and C1s, and it is activated by the binding of C1q to the Fc region of an antibody that is bound to a pathogen or damaged cell. Once activated, C1r undergoes a conformational change that allows it to cleave and activate C1s. Activated C1s then goes on to cleave and activate other components of the complement system, leading to the production of the membrane attack complex (MAC), which forms a pore in the membrane of the target cell and causes lysis.
Deficiencies or mutations in the genes encoding the proteins of the C1 complex can lead to immune disorders, including hereditary angioedema, which is characterized by recurrent episodes of swelling in various parts of the body.
Kaolin is not a medical term per se, but it is a mineral that has various applications in the medical field. Medically, kaolin is used as an ingredient in some over-the-counter (OTC) medications and clinical products, particularly in oral and topical formulations.
Medical definition: Kaolin is a natural hydrated aluminum silicate clay mineral (with the chemical formula Al2Si2O5(OH)4) used in medical applications as an antidiarrheal agent and as a component in various dermatological products for its absorbent, protective, and soothing properties.
Serum globulins are a group of proteins present in the liquid portion of blood, known as serum. They are produced by the immune system in response to foreign substances such as bacteria, viruses, and allergens. Serum globulins include several types of immunoglobulins (antibodies), complement components, and other proteins involved in the immune response.
The serum globulin level is often measured as part of a complete blood count (CBC) or a protein electrophoresis test. An elevated serum globulin level may indicate an ongoing infection, inflammation, or an autoimmune disorder. Conversely, a decreased level may suggest a liver or kidney disease, or a malnutrition condition. It is important to note that the interpretation of serum globulin levels should be done in conjunction with other laboratory and clinical findings.
CD55, also known as Decay-accelerating factor (DAF), is a protein that acts as an inhibitor of the complement system, which is a part of the immune system. It prevents the formation of the membrane attack complex (MAC) on host cells and tissues, thereby protecting them from damage caused by the complement activation. CD55 is found on the surface of many types of cells in the body, including red blood cells, white blood cells, and cells lining the blood vessels.
As an antigen, CD55 is a molecule that can be recognized by the immune system and stimulate an immune response. However, unlike some other antigens, CD55 does not typically elicit a strong immune response because it is a self-antigen, meaning it is normally present in the body and should not be targeted by the immune system.
In certain medical conditions, such as autoimmune disorders or transplant rejection, the immune system may mistakenly attack cells expressing CD55. In these cases, measuring the levels of CD55 antigens can provide valuable diagnostic information and help guide treatment decisions.
CD59 is a type of protein found on the surface of many cells in the human body, including red and white blood cells, that functions as an inhibitor of the complement system. The complement system is a part of the immune system that helps to eliminate pathogens such as bacteria and viruses from the body.
CD59 specifically inhibits the formation of the membrane attack complex (MAC), which is a protein structure that forms pores in the cell membrane and can lead to cell lysis or death. By preventing the formation of the MAC, CD59 helps to protect cells from complement-mediated damage.
As an antigen, CD59 is a molecule that can be recognized by the immune system and stimulate an immune response. However, because it is a self-protein found on normal human cells, CD59 is not typically targeted by the immune system unless there is some kind of dysregulation or abnormality.
In certain medical conditions, such as autoimmune disorders or transplant rejection, the immune system may mistakenly target CD59 or other self-proteins, leading to damage to healthy cells and tissues. In these cases, treatments may be necessary to modulate or suppress the immune response and prevent further harm.
Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.
Complement C5b is a protein complex that forms during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by marking them for destruction and attracting immune cells to the site of infection or injury.
The complement component C5 is cleaved into two fragments, C5a and C5b, during the activation of the complement system. C5a is a small peptide that acts as a chemoattractant, drawing immune cells to the site of inflammation. C5b, on the other hand, forms a complex with other complement components (C6, C7, C8, and C9) to create the membrane attack complex (MAC). The MAC inserts itself into the membrane of the target cell, forming a pore that disrupts the cell's integrity and leads to its lysis or destruction.
Therefore, Complement C5b is an important protein involved in the immune response, specifically in the terminal phase of complement activation, which results in the formation of the MAC and subsequent destruction of target cells.
Hydroxybenzoate ethers are a type of chemical compound that are commonly used as preservatives in pharmaceuticals, cosmetics, and food products. They are formed by the reaction between a hydroxybenzoic acid and an alcohol, resulting in the creation of an ether bond.
The term "hydroxybenzoate" refers to a class of compounds known as phenols, which contain a hydroxyl group (-OH) attached to a benzene ring. Examples of hydroxybenzoic acids include gallic acid, protocatechuic acid, and vanillic acid.
When these hydroxybenzoic acids react with an alcohol, such as ethanol or methanol, they form hydroxybenzoate ethers. The most common examples of hydroxybenzoate ethers used in medical applications include:
* Methylparaben (methyl 4-hydroxybenzoate)
* Ethylparaben (ethyl 4-hydroxybenzoate)
* Propylparaben (propyl 4-hydroxybenzoate)
* Butylparaben (butyl 4-hydroxybenzoate)
These compounds are effective antimicrobial agents and are used to prevent the growth of bacteria, yeasts, and molds in a variety of medical and consumer products. However, there is some concern that parabens may have estrogenic effects and potentially disrupt hormone function, although the evidence for this is not conclusive. As a result, some manufacturers have begun to phase out the use of parabens in their products.
Complement factor I
Complement control protein
Alternative complement pathway
C3-convertase
C5a peptidase
List of MeSH codes (D12.776.124)
Protein C
Streptococcus pyogenes
Complement Inactivator Proteins | Profiles RNS
Complement factor I - Wikipedia
Complement cascade and its inhibitors | Abcam
Cfi gene cDNA ORF clone, Rattus norvegicus(Norway rat) - GenScript
MeSH Browser
DeCS
Frontiers | The Immunogenetic Conundrum of Preeclampsia
Serpins. Medical search
Department of Orthopedics - Research output - Taipei Medical University
骨科學科 - 研究成果 - 臺北醫學大學
CFI gene: MedlinePlus Genetics
Complement C4 | Harvard Catalyst Profiles | Harvard Catalyst
Fact file for C4 binding protein α deficiency
Complement C9 | Profiles RNS
HSP47 Heat-Shock Proteins | Profiles RNS
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Pesquisa | Portal Regional da BVS
Structure-function mapping of BbCRASP-1, the key complement factor H and FHL-1 binding protein of Borrelia burgdorferi. -...
Pegcetacoplan: Uses, Interactions, Mechanism of Action | DrugBank Online
Mutational analyses of the BbCRASP-1 protein of Borrelia burgdorferi identify residues relevant for the architecture and...
21 CFR §866 Immunology And Microbiology Devices - Code of Federal Regulations
Alpha2-Plasmin Inhibitor Deficiency: Practice Essentials, Pathophysiology, Epidemiology
The OspE-related proteins inhibit complement deposition and enhance serum resistance of Borrelia burgdorferi, the lyme disease...
DeCS 2017 - July 04, 2017 version
LRP12 LDL receptor related protein 12 [Homo sapiens (human)] - Gene - NCBI
Plus it
Serum9
- Serum proteins that negatively regulate the cascade process of COMPLEMENT ACTIVATION. (uams.edu)
- Complement factor I (factor I) is a protein of the complement system, first isolated in 1966 in guinea pig serum, that regulates complement activation by cleaving cell-bound or fluid phase C3b and C4b. (wikipedia.org)
- Serum proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits. (lookformedical.com)
- The Contribution of Serum Complement Component 3 Levels to 90-Day Mortality in Living Donor Liver Transplantation. (harvard.edu)
- It interacts also with anticoagulant protein S and with serum amyloid P component. (lu.se)
- Complement-dependent cytotoxicity (CDC), which eliminates aberrant target cells through the assembly and complex formation of serum complement molecules, is one of the major effector functions of anticancer therapeutic antibodies. (bvsalud.org)
- Serum-resistant B. burgdorferi strains bind complement factor H (FH) and FH-like protein 1 (FHL-1) on the spirochaete surface. (ox.ac.uk)
- The OspE-related proteins inhibit complement deposition and enhance serum resistance of Borrelia burgdorferi, the lyme disease spirochete. (ouhsc.edu)
- ELISA tests are enzyme linked immunoassays to detect human, mouse or other proteins in serum, plasma, urine or biological fluids. (gentaur.com)
Gene8
- Complement factor I, also known as C3b/C4b inactivator, is a protein that in humans is encoded by the CFI gene. (wikipedia.org)
- Loss of function mutations in the Complement Factor I gene lead to low levels of factor I which results in increased complement activity. (wikipedia.org)
- Association of single nucleotide polymorphism in complement factor I gene with age-related macular degeneration]. (genscript.com)
- The CFI gene provides instructions for making a protein called complement factor I. This protein helps regulate a part of the body's immune response known as the complement system. (medlineplus.gov)
- At least 10 mutations in the CFI gene have been identified in people with complement factor I deficiency, a disorder characterized by immune system dysfunction. (medlineplus.gov)
- The CFI gene mutations identified in this disorder result in an abnormal or nonfunctional version of complement factor I. The defective protein allows uncontrolled activation of the complement system. (medlineplus.gov)
- This gene encodes a member of the low-density lipoprotein receptor related protein family. (nih.gov)
- The product of this gene is a transmembrane protein that is differentially expressed in many cancer cells. (nih.gov)
Inhibitor5
- Pegcetacoplan is a complement inhibitor indicated in the treatment of adults with paroxysmal nocturnal hemoglobinuria. (drugbank.com)
- Pegcetacoplan is a complement inhibitor indicated in the treatment of paroxysmal nocturnal hemoglobinuria (PNH). (drugbank.com)
- Pegcetacoplan is a complement C3 inhibitor that prevents complement-mediated hemolysis of red blood cells in patients with paroxysomal nocturnal hemoglobinuria. (drugbank.com)
- Alpha2-plasmin inhibitor (alpha2-PI), also known as alpha2-antiplasmin, is a protein that is primarily synthesized by the liver and is present in plasma and platelets. (medscape.com)
- The structure of C3c in complex with the complement inhibitor, compstatin, and use of this information for rational design or identification of complement-inhibiting drugs are disclosed. (justia.com)
C3BINA1
- It binds as a cofactor to C3b/C4b inactivator (C3bina), which then hydrolyzes the complement fragment C4b. (lu.se)
Borrelia2
- Structure-function mapping of BbCRASP-1, the key complement factor H and FHL-1 binding protein of Borrelia burgdorferi. (ox.ac.uk)
- Mutational analyses of the BbCRASP-1 protein of Borrelia burgdorferi identify residues relevant for the architecture and binding of host complement regulators FHL-1 and factor H. (ox.ac.uk)
Activation25
- Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host. (uams.edu)
- Factor I deficiency in turn leads to low levels of complement component 3 (C3), factor B, factor H and properdin in blood, due to unregulated activation of C3 convertase, and to low levels of IgG, due to loss of iC3b and C3dg production. (wikipedia.org)
- Learn about the three pathways lead to complement activation and some of their key inhibitors. (abcam.com)
- the classical pathway initiated by antibodies bound to the surface of foreign bodies and the alternative and lectin pathways that provide an antibody-independent mechanism for complement activation, induced by the presence of bacteria and other micro-organisms. (abcam.com)
- Mannan-binding lectin (MBL) and MBL-associated serine proteases (MASPs) are involved in the initial step of the lectin pathway of complement activation. (abcam.com)
- Following these cleavage events, complement pathway activation continues as in the classical pathway. (abcam.com)
- The alternative pathway of complement activation is in a constant state of low-level activation (known as tickover). (abcam.com)
- The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY . (nih.gov)
- When the intact C1 binds to at least two antibodies (involving C1q), C1r and C1s are sequentially activated, leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION . (nih.gov)
- Complement factor I and several related proteins protect healthy cells by preventing activation of the complement system when it is not needed. (medlineplus.gov)
- The lack (deficiency) of functional complement factor I protein allows uncontrolled activation of the complement system. (medlineplus.gov)
- A glycoprotein that is important in the activation of CLASSICAL COMPLEMENT PATHWAY. (harvard.edu)
- Cell-bound complement activation products associate with lupus severity in SLE. (harvard.edu)
- Complement Activation in Patients With Probable Systemic Lupus Erythematosus and Ability to Predict Progression to American College of Rheumatology-Classified Systemic Lupus Erythematosus. (harvard.edu)
- C4BP controls the classical pathway of complement activation. (lu.se)
- The alternative complement system pathway is spontaneously activated due to the absence of CD55, leading to activation of a C3 convertase that that cleaves C3 into C3a and C3b. (drugbank.com)
- 2 The resulting C3bBb can bind to other C3 proteins, leading to a positive feedback loop of complement activation. (drugbank.com)
- Clinical presentations are similar for the three types of MPGN, but they manifest somewhat different mechanisms of complement activation and predisposition to recur in kidney transplants. (medscape.com)
- This invention relates to activation of the complement cascade in the body. (justia.com)
- Inappropriate activation of the complement system leads to tissue injury causing or aggravating various pathological conditions, such as autoimmune diseases, burn injuries, Alzheimer's disease, stroke and heart attack, among others (reviewed by Sahu and Lambris, 2000). (justia.com)
- Several complement inhibitors currently under development target various steps in the complement activation pathways. (justia.com)
- describes the use of a phage-displayed combinatorial random peptide library to identify a 27-residue peptide that binds to C3 and inhibits complement activation. (justia.com)
- Compstatin inhibits complement response by preventing the proteolytic activation of C3 (Sahu et al. (justia.com)
- 1996). Activation of C3 by the C3 convertases is a central amplification step in complement activation. (justia.com)
- Because compstatin blocks this critical step of complement activation and because it is a small non-immunogenic peptide, compstatin has the potential to be developed into a therapeutic agent. (justia.com)
Molecular1
- Many of the substances under investigation possess the disadvantage of being a large molecular weight proteins that are difficult to manufacture and must be administered by infusion. (justia.com)
Subunit1
- G protein subunit beta 3 [Sou. (gsea-msigdb.org)
Genes1
- Complement genes contribute sex-biased vulnerability in diverse disorders. (harvard.edu)
Pathways1
- The normal complement system consists of the classic and alternative pathways. (medscape.com)
Regulators4
- This work demonstrates that pathogens interact with complement regulators in ways that are distinct from the mechanisms used by the host and are thus obvious targets for drug design. (ox.ac.uk)
- One central immune escape mechanism is the inactivation of the host complement attack by acquisition host complement regulators FHL-1 and factor H via complement regulator-acquiring surface proteins (BbCRASPs). (ox.ac.uk)
- Previously, 3 regions including the C terminus were identified as putative contact sites for the two complement regulators by the pepspot analysis. (ox.ac.uk)
- Single changes at 4 positions in region 1 either reduced (Lys136, Lys141, Glu147) or completely eliminated (Leu146) binding of both complement regulators. (ox.ac.uk)
Surface proteins1
- This binding is dependent on the expression of proteins termed complement-regulator acquiring surface proteins (CRASPs). (ox.ac.uk)
Mutations3
- The mutations result in abnormal, nonfunctional, or absent complement factor I. (medlineplus.gov)
- Characterization of mutations in complement factor I (CFI) associated with hemolytic uremic syndrome. (medlineplus.gov)
- Mapping the mutations onto the atomic structure of BbCRASP-1 reveals that, in contrast to earlier assumption, the C-terminal mutations act indirectly on FHL-1 and factor H binding, whilst the region 1 mutations map the site of direct complement regulator interaction. (ox.ac.uk)
Cascade2
- C1 is the first molecule in the classical complement cascade and comprises C1q and two molecules of C1r and C1s respectively. (abcam.com)
- mouse homolog is a regulatory serine proteinase of the complement cascade that cleaves C3b and C4b and inactivates them [RGD, Feb 2006]. (genscript.com)
Urine2
- A member of the serpin family of proteins that is found in plasma and urine. (lookformedical.com)
- The overactive complement system attacks certain kidney cells, which damages the kidneys and leads to a loss of protein in the urine (proteinuria). (medlineplus.gov)
CD591
- OBJECTIVES: This study aimed to evaluate the expression pattern of complement regulatory proteins (CRPs) CD46, CD59, and CD55 in HPV-positive (HPV+) & negative (HPV-) cervical cancer cell lines in search of a reliable differential biomarker. (bvsalud.org)
Component1
- The complement system is a heat-labile component of blood that confers bactericidal properties. (abcam.com)
Hemolytic uremic s1
- Atypical hemolytic uremic syndrome is caused by complement overactivation. (wikipedia.org)
CDNA2
- These sequences represent the protein coding region of the Cfi cDNA ORF which is encoded by the open reading frame (ORF) sequence. (genscript.com)
- E05 478 566 350 170 or Enzyme-Linked Immunosorbent Assays, E05 478 566 350 170 or Enzyme-Linked Immunosorbent Assays, Human proteins, cDNA and human recombinants are used in human reactive ELISA kits and to produce anti-human mono and polyclonal antibodies. (gentaur.com)
Deficiency2
- This condition, which may also occur in people with complement factor I deficiency, is characterized by kidney malfunction that can be serious or life-threatening. (medlineplus.gov)
- We report 2 children with distinct causes of polycythemia, 1 from systemic capillary leak syndrome (SCLS) and the other from protein-losing enteropathy (PLE) caused by CD55 deficiency. (bvsalud.org)
Plasmin3
- It is the principal plasmin inactivator in blood, rapidly forming a very stable complex with plasmin. (lookformedical.com)
- Plasminogen activators convert the zymogen plasminogen to the active enzyme plasmin, which then hydrolyzes susceptible arginine and lysine bonds in a variety of proteins. (medscape.com)
- Plasmin not only degrades fibrin, which is its principal substrate, but it also degrades fibrinogen, factors V and VIII, proteins involved in platelet adhesion (glycoprotein I and vWF), platelet aggregation (glycoprotein IIb/IIIa) and maintenance of platelet aggregates (thrombospondin, fibronectin, histidine-rich glycoprotein), and the attachment of platelets and fibrin to the endothelial surface. (medscape.com)
Antigen1
- mice injected intravenously with a commercially available extract of coxiella burnetii prepared for use as the antigen in the complement fixation diagnostic test for q fever were subsequently resistant to infection with babesia microti, babesia rodhaini, and plasmodium vinckei petteri. (liverpool.ac.uk)
Enzyme5
- the heavy chain plays an inhibitory role in maintaining the enzyme inactive until it meets the complex formed by the substrate (either C3b or C4b) and a cofactor protein (Factor H, C4b-binding protein, complement receptor 1, and membrane cofactor protein). (wikipedia.org)
- An enzyme that catalyzes the hydrolysis of proteins, including elastin. (lookformedical.com)
- The enzyme breaks down elastin, the specific protein of elastic fibers, and digests other proteins such as fibrin, hemoglobin, and albumin. (lookformedical.com)
- ELISA kit, ELISA, ELISAs Enzyme-linked immunosorbent assay 90320007 SNOMED code are used by the medical researcher for detection of human, mouse, … proteins are supplied in coated 96 well plates to be stored at +4°C. ELISA test kits can be sandwich ELISA. (gentaur.com)
- Therefore, in addition to enzyme activity, mRNA and/or protein levels should be measured to fully evaluate the P450 induction potential of a drug candidate. (aspetjournals.org)
System7
- The complement system is tightly regulated by inactivators that accelerate the decay of intermediates and certain cell surface receptors. (uams.edu)
- GenScript guarantees 100% sequence accuracy of all synthetic DNA constructs we deliver, but we do not guarantee protein expression in your experimental system. (genscript.com)
- Invading trophoblast cells will encounter maternal complement system (C) in the decidua and in the intervillous space. (frontiersin.org)
- The complement system is a group of proteins that work together to destroy foreign invaders (such as bacteria and viruses), trigger inflammation, and remove debris from cells and tissues. (medlineplus.gov)
- The unregulated activity of the complement system decreases blood levels of another complement protein called C3, reducing the immune system's ability to fight infections. (medlineplus.gov)
- Medical Records-Based Genetic Studies of the Complement System. (harvard.edu)
- the influence of the complement (c) system on plasmodial infections in vivo (plasmodium berghei in rats) and in vitro (plasmodium falciparum) has been determined. (liverpool.ac.uk)
Polypeptide1
- PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain). (lookformedical.com)
Receptor1
- G protein-coupled receptor 37. (gsea-msigdb.org)
Inhibitors2
- Alpha2-PI belongs to the serpin family of inhibitors, is synthesized by the liver, and is present in plasma as a single-chain protein at approximately half the concentration of plasminogen. (medscape.com)
- Mechanism-based P450 inhibitors can be characterized as displaying NADPH-, concentration-, and time-dependent quasi-irreversible or irreversible inactivation because of chemical modification of the heme and/or protein, and the inactivation rate is diminished in the presence of a competing substrate ( Silverman, 1998 ). (aspetjournals.org)
Transmembrane protein1
- transmembrane protein 1. (gsea-msigdb.org)
Subunits1
- Aplha, transcription related growth factors and stimulating factors or repressing nuclear factors are complex subunits of proteins involved in cell differentiation. (gentaur.com)
MeSH1
- Complement Inactivator Proteins" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (uams.edu)
Factor I protein1
- Then, factor I is cleaved by furin to yield the mature factor I protein, which is a disulfide-linked dimer of heavy chain (residues 19-335, 51 kDalton) and light chain (residues 340-583, 37 kDalton). (wikipedia.org)
Tertiary1
- The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. (lookformedical.com)
Source:HGN1
- docking protein 3 [Source:HGN. (gsea-msigdb.org)
MRNA2
- Rattus norvegicus complement factor I (Cfi), mRNA. (genscript.com)
- Induction of P450s can be demonstrated using one or more of a combination of different endpoints: mRNA, protein via Western blotting, and activity using a selective substrate. (aspetjournals.org)
Profiles2
- This graph shows the total number of publications written about "Complement Inactivator Proteins" by people in UAMS Profiles by year, and whether "Complement Inactivator Proteins" was a major or minor topic of these publications. (uams.edu)
- Below are the most recent publications written about "Complement Inactivator Proteins" by people in Profiles over the past ten years. (uams.edu)
Human3
- Overexpression of schizophrenia susceptibility factor human complement C4A promotes excessive synaptic loss and behavioral changes in mice. (harvard.edu)
- A functional proteomic method for the enrichment of peripheral membrane proteins reveals the collagen binding protein Hsp47 is exposed on the surface of activated human platelets. (umassmed.edu)
- Arguably, human hepatocytes provide the closest in vitro model to human liver by providing the full complement of xenobiotic-metabolizing enzymes and transporters. (aspetjournals.org)
Characterization1
- Transcriptome characterization by RNA-Seq reveals the involvement of the complement components in noise-traumatized rat cochleae. (genscript.com)
Complex3
- The functions of complement include the attraction of inflammatory cells, opsonization to promote phagocytosis, immune complex clearance and direct microbial killing through the formation of the membrane attack complex (MAC). (abcam.com)
- It also accelerates the degradation of the C4bc2a complex (C3 convertase) by dissociating the complement fragment C2a. (lu.se)
- ER membrane protein complex s. (gsea-msigdb.org)
Atomic structure2
Domain Protein1
- FIC domain protein adenylyltr. (gsea-msigdb.org)