Effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eucaryotic cells.
A zinc containing enzyme of the hydrolase class that catalyzes the removal of the N-terminal amino acid from most L-peptides, particularly those with N-terminal leucine residues but not those with N-terminal lysine or arginine residues. This occurs in tissue cell cytosol, with high activity in the duodenum, liver, and kidney. The activity of this enzyme is commonly assayed using a leucine arylamide chromogenic substrate such as leucyl beta-naphthylamide.
A formylated tripeptide originally isolated from bacterial filtrates that is positively chemotactic to polymorphonuclear leucocytes, and causes them to release lysosomal enzymes and become metabolically activated.
Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.
An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.
A transfer RNA which is specific for carrying methionine to sites on the ribosomes. During initiation of protein synthesis, tRNA(f)Met in prokaryotic cells and tRNA(i)Met in eukaryotic cells binds to the start codon (CODON, INITIATOR).
The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.
An enzyme of the oxidoreductase class that catalyzes the formation of L-TYROSINE, dihydrobiopterin, and water from L-PHENYLALANINE, tetrahydrobiopterin, and oxygen. Deficiency of this enzyme may cause PHENYLKETONURIAS and PHENYLKETONURIA, MATERNAL. EC 1.14.16.1.
Derivatives of formic acids. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are formed with a single carbon carboxy group.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A sulfur-containing essential L-amino acid that is important in many body functions.
A process of GENETIC TRANSLATION whereby the formation of a peptide chain is started. It includes assembly of the RIBOSOME components, the MESSENGER RNA coding for the polypeptide to be made, INITIATOR TRNA, and PEPTIDE INITIATION FACTORS; and placement of the first amino acid in the peptide chain. The details and components of this process are unique for prokaryotic protein biosynthesis and eukaryotic protein biosynthesis.
An enzyme that catalyzes the deamination of PHENYLALANINE to form trans-cinnamate and ammonia.
Enzymes that catalyze the transfer of an aminoacyl group from donor to acceptor resulting in the formation of an ester or amide linkage. EC 2.3.2.
A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952).
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
An essential branched-chain amino acid important for hemoglobin formation.
A subclass of EXOPEPTIDASES that act on the free N terminus end of a polypeptide liberating a single amino acid residue. EC 3.4.11.
A transfer RNA which is specific for carrying leucine to sites on the ribosomes in preparation for protein synthesis.
Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A group of compounds that are derivatives of phenylpyruvic acid which has the general formula C6H5CH2COCOOH, and is a metabolite of phenylalanine. (From Dorland, 28th ed)
A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
Enzymes that catalyze the formation of a carbon-carbon double bond by the elimination of AMMONIA. EC 4.3.1.
An enzyme that catalyzes the conversion of prephenate to phenylpyruvate with the elimination of water and carbon dioxide. In the enteric bacteria this enzyme also possesses chorismate mutase activity, thereby catalyzing the first two steps in the biosynthesis of phenylalanine. EC 4.2.1.51.
A natural product that has been considered as a growth factor for some insects.
Compounds based on 2-amino-4-hydroxypteridine.
The rate dynamics in chemical or physical systems.
An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.
Amino acids containing an aromatic side chain.
An enzyme that activates phenylalanine with its specific transfer RNA. EC 6.1.1.20.
A condition occurring in untreated or partially treated females with PHENYLKETONURIA when they become pregnant. This may result in damages to the FETUS, including MICROCEPHALY; MENTAL RETARDATION; congenital heart disease; FETAL GROWTH RETARDATION; and CRANIOFACIAL ABNORMALITIES. (From Am J Med Genet 1997 Mar 3;69(1):89-95)
A selective and irreversible inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the biosynthesis of serotonin (5-HYDROXYTRYPTAMINE). Fenclonine acts pharmacologically to deplete endogenous levels of serotonin.
3-(p-Fluorophenyl)-alanine.
An isomerase that catalyzes the conversion of chorismic acid to prephenic acid. EC 5.4.99.5.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
A family of G-protein-coupled receptors that was originally identified by its ability to bind N-formyl peptides such as N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE. Since N-formyl peptides are found in MITOCHONDRIA and BACTERIA, this class of receptors is believed to play a role in mediating cellular responses to cellular damage and bacterial invasion. However, non-formylated peptide ligands have also been found for this receptor class.
Chemical substances that attract or repel cells. The concept denotes especially those factors released as a result of tissue injury, microbial invasion, or immunologic activity, that attract LEUKOCYTES; MACROPHAGES; or other cells to the site of infection or insult.
Peptides composed of between two and twelve amino acids.

Yops of Yersinia enterocolitica inhibit receptor-dependent superoxide anion production by human granulocytes. (1/2264)

The virulence plasmid-borne genes encoding Yersinia adhesin A (YadA) and several Yersinia secreted proteins (Yops) are involved in the inhibition of phagocytosis and killing of Yersinia enterocolitica by human granulocytes. One of these Yops, YopH, dephosphorylates multiple tyrosine-phosphorylated proteins in eukaryotic cells and is involved in the inhibition of phagocytosis of Y. enterocolitica by human granulocytes. We investigated whether antibody- and complement-opsonized plasmid-bearing (pYV+) Y. enterocolitica inhibits O2- production by human granulocytes in response to various stimuli and whether YopH is involved. Granulocytes were preincubated with mutant strains unable to express YadA or to secrete Yops or YopH. O2- production by granulocytes during stimulation was assessed by measuring the reduction of ferricytochrome c. PYV+ Y. enterocolitica inhibited O2- production by granulocytes incubated with opsonized Y. enterocolitica or N-formyl-Met-Leu-Phe (f-MLP). This inhibitory effect mediated by pYV did not affect receptor-independent O2- production by granulocytes in response to phorbol myristate acetate, indicating that NADPH activity remained unaffected after activation of protein kinase C. The inhibition of f-MLP-induced O2- production by granulocytes depends on the secretion of Yops and not on the expression of YadA. Insertional inactivation of the yopH gene abrogated the inhibition of phagocytosis of antibody- and complement-opsonized Y. enterocolitica by human granulocytes but not of the f-MLP-induced O2- production by granulocytes or tyrosine phosphorylation of granulocyte proteins. These findings suggest that the specific targets for YopH are not present in f-MLP receptor-linked signal transduction and that other Yop-mediated mechanisms are involved.  (+info)

Role of the extracellular signal-regulated protein kinase cascade in human neutrophil killing of Staphylococcus aureus and Candida albicans and in migration. (2/2264)

Killing of Staphylococcus aureus and Candida albicans by neutrophils involves adherence of the microorganisms, phagocytosis, and a collaborative action of oxygen reactive species and components of the granules. While a number of intracellular signalling pathways have been proposed to regulate neutrophil responses, the extent to which each pathway contributes to the killing of S. aureus and C. albicans has not been clearly defined. We have therefore examined the effect of blocking one such pathway, the extracellular signal-regulated protein kinase (ERK) cascade, using the specific inhibitor of the mitogen-activated protein kinase/ERK kinase, PD98059, on the ability of human neutrophils to kill S. aureus and C. albicans. Our data demonstrate the presence of ERK2 and a 43-kDa form of ERK but not ERK1 in human neutrophils. Upon stimulation with formyl methionyl leucyl phenylalanine (fMLP), the activities of both ERK2 and the 43-kDa form were stimulated. Despite abrogating the activity of both ERK forms, PD98059 only slightly reduced the ability of neutrophils to kill S. aureus or C. albicans. This is consistent with our finding that PD98059 had no effect on neutrophil adherence or degranulation, although pretreatment of neutrophils with PD98059 inhibited fMLP-stimulated superoxide production by 50%, suggesting that a change in superoxide production per se is not strictly correlated with microbicidal activity. However, fMLP-stimulated chemokinesis was markedly inhibited, while random migration and fMLP-stimulated chemotaxis were partially inhibited, by PD98059. These data demonstrate, for the first time, that the ERK cascade plays only a minor role in the microbicidal activity of neutrophils and that the ERK cascade is involved primarily in regulating neutrophil migration in response to fMLP.  (+info)

Suppression of atherosclerotic development in Watanabe heritable hyperlipidemic rabbits treated with an oral antiallergic drug, tranilast. (3/2264)

BACKGROUND: Inflammatory and immunological responses of vascular cells have been shown to play a significant role in the progression of atheromatous formation. Tranilast [N-(3,4-dimethoxycinnamoyl) anthranillic acid] inhibits release of cytokines and chemical mediators from various cells, including macrophages, leading to suppression of inflammatory and immunological responses. This study tested whether tranilast may suppress atheromatous formation in Watanabe heritable hyperlipidemic (WHHL) rabbits. METHODS AND RESULTS: WHHL rabbits (2 months old) were given either 300 mg x kg-1 x d-1 of tranilast (Tranilast, n=12) or vehicle (Control, n=13) PO for 6 months. Tranilast treatment was found to suppress the aortic area covered with plaque. Immunohistochemical analysis showed that there was no difference in the percentage of the RAM11-positive macrophage area and the frequency of CD5-positive cells (T cells) in intimal plaques between Tranilast and Control. Major histocompatibility complex (MHC) class II expression in macrophages and interleukin-2 (IL-2) receptor expression in T cells, as markers of the immunological activation in these cells, was suppressed in atheromatous plaque by tranilast treatment. Flow cytometry analysis of isolated human and rabbit peripheral blood mononuclear cells showed that an increase in expression both of MHC class II antigen on monocytes by incubation with interferon-gamma and of IL-2 receptor on T cells by IL-2 was suppressed by the combined incubation with tranilast. CONCLUSIONS: The results indicate that tranilast suppresses atherosclerotic development partly through direct inhibition of immunological activation of monocytes/macrophages and T cells in the atheromatous plaque.  (+info)

Effect of nitric oxide donors on oxygen-dependent cytotoxic responses mediated by neutrophils. (4/2264)

We analyzed the effect of nitric oxide (NO) on oxygen-dependent cytotoxic responses mediated by neutrophils against unopsonized erythrocytes using three NO donors: S-nitrosoglutathione (GSNO), S-nitroso-N-acetylpenicillamine (SNAP), and sodium nitroprusside (SNP). Neutrophils were treated with these compounds for 1-2 min at 37 degrees C and cytotoxicity was then triggered in the presence of NO donors by precipitating immune complexes, aggregated IgG, the chemotactic peptide FMLP, or opsonized zymosan. GSNO induced, in all cases, a marked increase in cytotoxic responses, while SNAP moderately increased cytotoxicity triggered by immune complexes, aggregated IgG, or Z, opsonized zymosen, without modifying those responses induced by FMLP. By contrast, SNP dramatically suppressed cytotoxicity triggered by all of the stimuli assessed. The enhancing effects mediated by GSNO and SNAP did not depend on the stimulation of guanylyl cyclase and were prevented by the NO scavengers hemoglobin and PTIO (2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl 3-oxide). The inhibitory activity of SNP, on the other hand, was not prevented by NO scavengers, suggesting that it cannot be ascribed to the release of NO. In another set of experiments, neutrophils were pretreated with GSNO or SNAP for different times. Then cells were washed to remove NO donors from the culture medium, and cytotoxicity was triggered by different stimuli. It was found that neutrophils must be pretreated with NO donors for at least 4 h to increase cytotoxic responses, and pretreatment for longer periods (i.e., 8 or 18 h) further increased cytotoxicity. Not only cytotoxic responses, but also the production of O2- and H2O2, and the release of myeloperoxidase were increased under these conditions.  (+info)

A functional granulocyte colony-stimulating factor receptor is required for normal chemoattractant-induced neutrophil activation. (5/2264)

Granulocyte colony-stimulating factor (G-CSF) is a hematopoietic growth factor that is widely used to treat neutropenia. In addition to stimulating polymorphonuclear neutrophil (PMN) production, G-CSF may have significant effects on PMN function. Because G-CSF receptor (G-CSFR)-deficient mice do not have the expected neutrophilia after administration of human interleukin-8 (IL-8), we examined the effect of the loss of G-CSFR on IL-8-stimulated PMN function. Compared with wild-type PMNs, PMNs isolated from G-CSFR-deficient mice demonstrated markedly decreased chemotaxis to IL-8. PMN emigration into the skin of G-CSFR-deficient mice in response to IL-8 was also impaired. Significant chemotaxis defects were also seen in response to N-formyl-methionyl-leucyl-phenylalanine, zymosan-activated serum, or macrophage inflammatory protein-2. The defective chemotactic response to IL-8 does not appear to be due to impaired chemoattractant receptor function, as the number of IL-8 receptors and chemoattractant-induced calcium influx, actin polymerization, and release of gelatinase B were comparable to those of wild-type PMNs. Chemoattractant-induced adhesion of G-CSFR-deficient PMNs was significantly impaired, suggesting a defect in beta2-integrin activation. Collectively, these data demonstrate that selective defects in PMN activation are present in G-CSFR-deficient mice and indicate that G-CSF plays an important role in regulating PMN chemokine responsiveness.  (+info)

Differential regulation of beta1 integrins by chemoattractants regulates neutrophil migration through fibrin. (6/2264)

Chemoattractants differ in their capacity to stimulate neutrophils to adhere to and to migrate through matrices containing fibrin. Formyl methionyl leucyl phenylalanine (fMLP) stimulates neutrophils to adhere closely to, but not to migrate into, fibrin gels. Leukotriene B4 (LTB4) stimulates neutrophils to adhere loosely to and to migrate through fibrin gels. We report that alpha5beta1 integrins regulate the different migratory behaviors on fibrin gels of neutrophils in response to these chemoattractants. fMLP, but not LTB4, activated neutrophil beta1 integrins, as measured by binding of mAb 15/7 to an activation epitope on the beta1 integrins. Antibodies or peptides that block alpha5beta1 integrins prevented fMLP-stimulated neutrophils from forming zones of close apposition on fibrin and reversed fMLP's inhibitory effect on neutrophil chemotaxis through fibrin. In contrast, neither peptides nor antibodies that block beta1 integrins affected the capacity of LTB4-stimulated neutrophils to form zones of loose apposition or to migrate through fibrin gels. These results suggest that chemoattractants generate at least two different messages that direct neutrophils, and perhaps other leukocytes, to accumulate at specific anatomic sites: a general message that induces neutrophils to crawl and a specific message that prepares neutrophils to stop when they contact appropriate matrix proteins for activated beta1 integrins.  (+info)

Activation of the granule pool of the NADPH oxidase accelerates apoptosis in human neutrophils. (7/2264)

Oxidative stress induces apoptosis in many types of cells, including human neutrophils. Our objective was to determine whether reactive oxygen species (ROS) produced by activated neutrophils are associated with accelerated apoptosis. Exposing neutrophils to ionomycin or phorbol myristate acetate (PMA) induced intracellular H2O2 production and rapid onset of apoptosis, measured as condensed chromatin, cellular shrinkage, and DNA fragmentation. Neutrophils activated with formyl-methionyl-leucyl-phenylalanine (fMLP) generated mainly extracellular H2O2 and did not undergo apoptosis. Exogenously added H2O2, together with the catalase blocker sodium azide, induced apoptosis to the same extent and with similar kinetics as PMA and ionomycin. Adenosine inhibited ionomycin-induced intracellular H2O2 production and apoptosis. Neither PMA nor ionomycin caused apoptosis in dimethyl sulfoxide-differentiated HL-60 cells, which are incapable of intracellular H2O2 production, whereas H2O2 induced apoptosis more efficiently in these cells than in neutrophils. We propose that activated neutrophils use intracellularly formed H2O2 to commit suicide.  (+info)

Modulation of formyl peptide receptor expression by IL-10 in human monocytes and neutrophils. (8/2264)

IL-10, originally described as a cytokine synthesis inhibitory factor, is secreted by a number of cells of the immune system, including monocytes and T cells. Although IL-10 is being assigned as an immunosuppressive cytokine, our study showed that FMLP-R mRNA was rapidly up-regulated by exposure of monocytes to graded concentrations of this cytokine, with maximal (three- to fourfold) stimulation with 10 ng/ml. The effect was rapid, being observable as early as 1 h of treatment with IL-10, maximal between 2 and 4 h, and still evident after 24 h and was associated with an increase of receptor expression on the cell surface as assessed by flow cytometry analysis. Pretreatment of monocytes with actinomycin D completely abrogated the effect of IL-10, suggesting a transcriptional regulation. Moreover, IL-10-treated monocytes showed a significantly enhanced functional responsiveness to FMLP with enhanced (three- to fourfold) chemotaxis and augmented (twofold) intracellular calcium mobilization. In polymorphonuclear neutrophils (PMN), IL-10 also mediated a twofold augmentation of FMLP-R expression. In parallel experiments, we observed that IL-10 could differentially modulate other chemotactic receptors. Hence, we observed that IL-10 augmented two-to threefold platelet-activating factor receptor (PAF-R) expression, whereas it had no significant effect on the fifth component of complement (C5a) receptor (C5a-R) expression. Collectively, our results demonstrate that IL-10 may play an important role in inflammatory process through modulation of chemotactic receptor expression.  (+info)

N-Formylmethionine (fMet) is not a medical term per se, but rather a biochemical term. It is the formylated derivative of methionine, which is one of the twenty standard amino acids, and it plays a crucial role in the initiation of protein synthesis in prokaryotes and organelles of eukaryotic cells, such as mitochondria and chloroplasts.

In the context of medical research or clinical laboratory reports, you might encounter fMet in relation to bacterial infections, proteomics, or mitochondrial function. For example, formylated methionine residues on bacterial peptides can stimulate immune responses and are recognized by specific receptors on human immune cells, which can have implications for understanding infectious diseases and inflammation.

To provide a concise definition:
N-Formylmethionine (fMet) is the formylated derivative of methionine, primarily known for its role as the initiator amino acid in protein synthesis in prokaryotes and certain organelles of eukaryotic cells.

Leucyl aminopeptidase (LAP) is an enzyme that plays a role in the metabolism and breakdown of proteins. It is found in various tissues and organs throughout the body, including the small intestine, liver, and kidneys. LAP specifically catalyzes the removal of leucine, a type of amino acid, from the N-terminus (the beginning) of peptides and proteins. This enzyme is important for the proper digestion and absorption of dietary proteins, as well as for the regulation of various physiological processes in the body. Abnormal levels or activity of LAP have been implicated in certain diseases, such as cancer and liver disease.

N-Formylmethionine Leucyl-Phenylalanine (fMLP) is not a medical condition, but rather a synthetic peptide that is often used in laboratory settings for research purposes. It is a formylated methionine residue linked to a leucine and phenylalanine tripeptide.

fMLP is a potent chemoattractant for certain types of white blood cells, including neutrophils and monocytes. When these cells encounter fMLP, they are stimulated to migrate towards the source of the peptide and release various inflammatory mediators. As such, fMLP is often used in studies of inflammation, immune cell function, and signal transduction pathways.

It's important to note that while fMLP has important research applications, it is not a substance that would be encountered or used in clinical medicine.

Neutrophils are a type of white blood cell that are part of the immune system's response to infection. They are produced in the bone marrow and released into the bloodstream where they circulate and are able to move quickly to sites of infection or inflammation in the body. Neutrophils are capable of engulfing and destroying bacteria, viruses, and other foreign substances through a process called phagocytosis. They are also involved in the release of inflammatory mediators, which can contribute to tissue damage in some cases. Neutrophils are characterized by the presence of granules in their cytoplasm, which contain enzymes and other proteins that help them carry out their immune functions.

Phenylalanine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through diet or supplementation. It's one of the building blocks of proteins and is necessary for the production of various molecules in the body, such as neurotransmitters (chemical messengers in the brain).

Phenylalanine has two forms: L-phenylalanine and D-phenylalanine. L-phenylalanine is the form found in proteins and is used by the body for protein synthesis, while D-phenylalanine has limited use in humans and is not involved in protein synthesis.

Individuals with a rare genetic disorder called phenylketonuria (PKU) must follow a low-phenylalanine diet or take special medical foods because they are unable to metabolize phenylalanine properly, leading to its buildup in the body and potential neurological damage.

Transfer RNA (tRNA) is a type of RNA molecule that plays a crucial role in protein synthesis, the process by which cells create proteins. During protein synthesis, tRNAs serve as adaptors, translating the genetic code present in messenger RNA (mRNA) into the corresponding amino acids required to build a protein.

Each tRNA molecule has an anticodon region that can base-pair with specific codons (three-nucleotide sequences) on the mRNA. At the other end of the tRNA is the acceptor stem, which contains a binding site for the corresponding amino acid. When an amino acid attaches to the tRNA, it forms an ester bond between the carboxyl group of the amino acid and the 3'-hydroxyl group of the ribose in the tRNA. This aminoacylated tRNA then participates in the translation process, delivering the amino acid to the growing polypeptide chain at the ribosome.

In summary, transfer RNA (tRNA) is a type of RNA molecule that facilitates protein synthesis by transporting and delivering specific amino acids to the ribosome for incorporation into a polypeptide chain, based on the codon-anticodon pairing between tRNAs and messenger RNA (mRNA).

Transfer RNA (tRNA) is a type of RNA molecule that plays a crucial role in protein synthesis, the process by which cells create proteins. In protein synthesis, tRNAs serve as adaptors, translating the genetic code present in messenger RNA (mRNA) into the corresponding amino acids required to build a protein.

Each tRNA molecule has a distinct structure, consisting of approximately 70-90 nucleotides arranged in a cloverleaf shape with several loops and stems. The most important feature of a tRNA is its anticodon, a sequence of three nucleotides located in one of the loops. This anticodon base-pairs with a complementary codon on the mRNA during translation, ensuring that the correct amino acid is added to the growing polypeptide chain.

Before tRNAs can participate in protein synthesis, they must be charged with their specific amino acids through an enzymatic process involving aminoacyl-tRNA synthetases. These enzymes recognize and bind to both the tRNA and its corresponding amino acid, forming a covalent bond between them. Once charged, the aminoacyl-tRNA complex is ready to engage in translation and contribute to protein formation.

In summary, transfer RNA (tRNA) is a small RNA molecule that facilitates protein synthesis by translating genetic information from messenger RNA into specific amino acids, ultimately leading to the creation of functional proteins within cells.

Phenylalanine Hydroxylase (PAH) is an enzyme that plays a crucial role in the metabolism of the essential amino acid phenylalanine. This enzyme is primarily found in the liver and is responsible for converting phenylalanine into tyrosine, another amino acid. PAH requires a cofactor called tetrahydrobiopterin (BH4) to function properly.

Defects or mutations in the gene that encodes PAH can lead to a genetic disorder known as Phenylketonuria (PKU). In PKU, the activity of PAH is significantly reduced or absent, causing an accumulation of phenylalanine in the body. If left untreated, this condition can result in severe neurological damage and intellectual disability due to the toxic effects of high phenylalanine levels on the developing brain. A strict low-phenylalanine diet and regular monitoring of blood phenylalanine levels are essential for managing PKU and preventing associated complications.

I'm sorry for any confusion, but "Formates" is not a recognized term in medical terminology. It is possible that you may be referring to "formic acid" or "formate," which are terms used in chemistry and biochemistry. Formic acid is a colorless, pungent, and corrosive liquid with the chemical formula HCOOH. Its salts are called formates.

Formate is the anion (negatively charged ion) of formic acid, with the chemical formula HCOO-. Formate can be found in various biological systems and is involved in several metabolic processes. If you could provide more context or clarify your question, I would be happy to help further.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

Methionine is an essential amino acid, which means that it cannot be synthesized by the human body and must be obtained through the diet. It plays a crucial role in various biological processes, including:

1. Protein synthesis: Methionine is one of the building blocks of proteins, helping to create new proteins and maintain the structure and function of cells.
2. Methylation: Methionine serves as a methyl group donor in various biochemical reactions, which are essential for DNA synthesis, gene regulation, and neurotransmitter production.
3. Antioxidant defense: Methionine can be converted to cysteine, which is involved in the formation of glutathione, a potent antioxidant that helps protect cells from oxidative damage.
4. Homocysteine metabolism: Methionine is involved in the conversion of homocysteine back to methionine through a process called remethylation, which is essential for maintaining normal homocysteine levels and preventing cardiovascular disease.
5. Fat metabolism: Methionine helps facilitate the breakdown and metabolism of fats in the body.

Foods rich in methionine include meat, fish, dairy products, eggs, and some nuts and seeds.

Peptide chain initiation in translational terms refers to the process by which the synthesis of a protein begins on a ribosome. This is the first step in translation, where the small ribosomal subunit binds to an mRNA molecule at the start codon (usually AUG), bringing with it the initiator tRNA charged with a specific amino acid (often N-formylmethionine in prokaryotes or methionine in eukaryotes). The large ribosomal subunit then joins this complex, forming a functional initiation complex. This marks the beginning of the elongation phase, where subsequent amino acids are added to the growing peptide chain until termination is reached.

Phenylalanine Ammonia-Lyase (PAL) is a enzyme that catalyzes the non-oxidative deamination of phenylalanine to trans-cinamic acid, releasing ammonia in the process. This reaction is a key step in the biosynthesis of various aromatic compounds in plants and microorganisms. In humans, PAL is not normally present, but its introduction through gene therapy has been studied as a potential treatment for phenylketonuria (PKU), a genetic disorder characterized by an inability to metabolize phenylalanine properly, leading to its accumulation in the body and potential neurological damage.

Aminoacyltransferases are a group of enzymes that play a crucial role in protein synthesis. They are responsible for transferring amino acids to their corresponding tRNAs (transfer RNAs) during the process of translation. This important step allows the genetic code contained within mRNA (messenger RNA) to be translated into a specific sequence of amino acids, which ultimately forms a protein.

There are two main types of aminoacyltransferases:

1. Aminoacyl-tRNA synthetases: These enzymes catalyze the attachment of an amino acid to its corresponding tRNA molecule. Each aminoacyl-tRNA synthetase is specific to a particular amino acid and ensures that the correct amino acid is linked to the appropriate tRNA. This reaction involves two steps: first, the activation of the amino acid by forming an aminoacyl-AMP (aminoacyl adenosine monophosphate) intermediate, followed by the transfer of the activated amino acid to the 3' end of the tRNA.

2. Aminoacyl-tRNA editing enzymes: These enzymes are responsible for correcting any mistakes made during the charging process by aminoacyl-tRNA synthetases. If an incorrect amino acid is attached to a tRNA, these enzymes can remove and replace it with the correct one. This ensures the fidelity of protein synthesis and prevents errors in the resulting polypeptide chain.

In summary, aminoacyltransferases are essential for accurate protein synthesis, as they facilitate the transfer of amino acids to their corresponding tRNAs during translation. Aminoacyl-tRNA synthetases catalyze this process, while aminoacyl-tRNA editing enzymes correct any mistakes made during charging.

Phenylketonurias (PKU) is a genetic disorder characterized by the body's inability to properly metabolize the amino acid phenylalanine, due to a deficiency of the enzyme phenylalanine hydroxylase. This results in a buildup of phenylalanine in the blood and other tissues, which can cause serious neurological problems if left untreated.

The condition is typically detected through newborn screening and can be managed through a strict diet that limits the intake of phenylalanine. If left untreated, PKU can lead to intellectual disability, seizures, behavioral problems, and other serious health issues. In some cases, medication or a liver transplant may also be necessary to manage the condition.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Leucine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through the diet. It is one of the three branched-chain amino acids (BCAAs), along with isoleucine and valine. Leucine is critical for protein synthesis and muscle growth, and it helps to regulate blood sugar levels, promote wound healing, and produce growth hormones.

Leucine is found in various food sources such as meat, dairy products, eggs, and certain plant-based proteins like soy and beans. It is also available as a dietary supplement for those looking to increase their intake for athletic performance or muscle recovery purposes. However, it's important to consult with a healthcare professional before starting any new supplement regimen.

Aminopeptidases are a group of enzymes that catalyze the removal of amino acids from the N-terminus of polypeptides and proteins. They play important roles in various biological processes, including protein degradation, processing, and activation. Aminopeptidases are classified based on their specificity for different types of amino acids and the mechanism of their action. Some of the well-known aminopeptidases include leucine aminopeptidase, alanyl aminopeptidase, and arginine aminopeptidase. They are widely distributed in nature and found in various tissues and organisms, including bacteria, plants, and animals. In humans, aminopeptidases are involved in several physiological functions, such as digestion, immune response, and blood pressure regulation.

A transfer RNA (tRNA) molecule that carries the amino acid leucine is referred to as "tRNA-Leu." This specific tRNA molecule recognizes and binds to a codon (a sequence of three nucleotides in mRNA) during protein synthesis or translation. In this case, tRNA-Leu can recognize and pair with any of the following codons: UUA, UUG, CUU, CUC, CUA, and CUG. Once bound to the mRNA at the ribosome, leucine is added to the growing polypeptide chain through the action of aminoacyl-tRNA synthetase enzymes that catalyze the attachment of specific amino acids to their corresponding tRNAs. This ensures the accurate and efficient production of proteins based on genetic information encoded in mRNA.

Acyltransferases are a group of enzymes that catalyze the transfer of an acyl group (a functional group consisting of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydrogen atom) from one molecule to another. This transfer involves the formation of an ester bond between the acyl group donor and the acyl group acceptor.

Acyltransferases play important roles in various biological processes, including the biosynthesis of lipids, fatty acids, and other metabolites. They are also involved in the detoxification of xenobiotics (foreign substances) by catalyzing the addition of an acyl group to these compounds, making them more water-soluble and easier to excrete from the body.

Examples of acyltransferases include serine palmitoyltransferase, which is involved in the biosynthesis of sphingolipids, and cholesteryl ester transfer protein (CETP), which facilitates the transfer of cholesteryl esters between lipoproteins.

Acyltransferases are classified based on the type of acyl group they transfer and the nature of the acyl group donor and acceptor molecules. They can be further categorized into subclasses based on their sequence similarities, three-dimensional structures, and evolutionary relationships.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Phenylpyruvic acid is not a medical condition, but rather a chemical compound that is produced in the body. It is a byproduct of phenylalanine metabolism, an essential amino acid that cannot be synthesized by the human body and must be obtained through dietary sources such as proteins.

In some rare genetic disorders, such as phenylketonuria (PKU), the body is unable to properly metabolize phenylalanine due to a deficiency or malfunction of the enzyme phenylalanine hydroxylase. As a result, phenylpyruvic acid and other toxic byproducts accumulate in the body, leading to various health problems such as intellectual disability, seizures, and behavioral issues.

Therefore, the medical relevance of phenylpyruvic acid lies in its association with certain metabolic disorders, particularly PKU, and its potential use as a diagnostic marker for these conditions.

Tyrosine is an non-essential amino acid, which means that it can be synthesized by the human body from another amino acid called phenylalanine. Its name is derived from the Greek word "tyros," which means cheese, as it was first isolated from casein, a protein found in cheese.

Tyrosine plays a crucial role in the production of several important substances in the body, including neurotransmitters such as dopamine, norepinephrine, and epinephrine, which are involved in various physiological processes, including mood regulation, stress response, and cognitive functions. It also serves as a precursor to melanin, the pigment responsible for skin, hair, and eye color.

In addition, tyrosine is involved in the structure of proteins and is essential for normal growth and development. Some individuals may require tyrosine supplementation if they have a genetic disorder that affects tyrosine metabolism or if they are phenylketonurics (PKU), who cannot metabolize phenylalanine, which can lead to elevated tyrosine levels in the blood. However, it is important to consult with a healthcare professional before starting any supplementation regimen.

Amino acids are organic compounds that serve as the building blocks of proteins. They consist of a central carbon atom, also known as the alpha carbon, which is bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (H), and a variable side chain (R group). The R group can be composed of various combinations of atoms such as hydrogen, oxygen, sulfur, nitrogen, and carbon, which determine the unique properties of each amino acid.

There are 20 standard amino acids that are encoded by the genetic code and incorporated into proteins during translation. These include:

1. Alanine (Ala)
2. Arginine (Arg)
3. Asparagine (Asn)
4. Aspartic acid (Asp)
5. Cysteine (Cys)
6. Glutamine (Gln)
7. Glutamic acid (Glu)
8. Glycine (Gly)
9. Histidine (His)
10. Isoleucine (Ile)
11. Leucine (Leu)
12. Lysine (Lys)
13. Methionine (Met)
14. Phenylalanine (Phe)
15. Proline (Pro)
16. Serine (Ser)
17. Threonine (Thr)
18. Tryptophan (Trp)
19. Tyrosine (Tyr)
20. Valine (Val)

Additionally, there are several non-standard or modified amino acids that can be incorporated into proteins through post-translational modifications, such as hydroxylation, methylation, and phosphorylation. These modifications expand the functional diversity of proteins and play crucial roles in various cellular processes.

Amino acids are essential for numerous biological functions, including protein synthesis, enzyme catalysis, neurotransmitter production, energy metabolism, and immune response regulation. Some amino acids can be synthesized by the human body (non-essential), while others must be obtained through dietary sources (essential).

Ammonia-lyases are a class of enzymes that catalyze the removal of an amino group from a substrate, releasing ammonia in the process. These enzymes play important roles in various biological pathways, including the biosynthesis and degradation of various metabolites such as amino acids, carbohydrates, and aromatic compounds.

The reaction catalyzed by ammonia-lyases typically involves the conversion of an alkyl or aryl group to a carbon-carbon double bond through the elimination of an amine group. This reaction is often reversible, allowing the enzyme to also catalyze the addition of an amino group to a double bond.

Ammonia-lyases are classified based on the type of substrate they act upon and the mechanism of the reaction they catalyze. Some examples of ammonia-lyases include aspartate ammonia-lyase, which catalyzes the conversion of aspartate to fumarate, and tyrosine ammonia-lyase, which converts tyrosine to p-coumaric acid.

These enzymes are important in both plant and animal metabolism and have potential applications in biotechnology and industrial processes.

Prephenate Dehydratase is not a medical term per se, but rather a biochemical term. It's a type of enzyme involved in the metabolic pathway known as the shikimate pathway, which is responsible for the biosynthesis of aromatic amino acids in bacteria, fungi, and plants.

Prephenate Dehydratase specifically catalyzes the conversion of prephenate to phenylpyruvate and water in this pathway. This reaction is a key step in the synthesis of phenylalanine, one of the aromatic amino acids.

In a medical context, understanding the function of Prephenate Dehydratase may be relevant in fields such as microbiology or plant biochemistry, but it does not have direct clinical significance for human health diagnoses or treatments.

Biopterin is a type of pteridine compound that acts as a cofactor in various biological reactions, particularly in the metabolism of amino acids such as phenylalanine and tyrosine. It plays a crucial role in the production of neurotransmitters like dopamine, serotonin, and noradrenaline. Biopterin exists in two major forms: tetrahydrobiopterin (BH4) and dihydrobiopterin (BH2). BH4 is the active form that participates in enzymatic reactions, while BH2 is an oxidized form that can be reduced back to BH4 by the action of dihydrobiopterin reductase.

Deficiencies in biopterin metabolism have been linked to several neurological disorders, including phenylketonuria (PKU), dopamine-responsive dystonia, and certain forms of autism. In these conditions, the impaired synthesis or recycling of biopterin can lead to reduced levels of neurotransmitters, causing various neurological symptoms.

Pterins are a group of naturally occurring pigments that are derived from purines. They are widely distributed in various organisms, including bacteria, fungi, and animals. In humans, pterins are primarily found in the eye, skin, and hair. Some pterins have been found to play important roles as cofactors in enzymatic reactions and as electron carriers in metabolic pathways.

Abnormal levels of certain pterins can be indicative of genetic disorders or other medical conditions. For example, an excess of biopterin, a type of pterin, is associated with phenylketonuria (PKU), a genetic disorder that affects the body's ability to metabolize the amino acid phenylalanine. Similarly, low levels of neopterin, another type of pterin, can be indicative of immune system dysfunction or certain types of cancer.

Medical professionals may measure pterin levels in blood, urine, or other bodily fluids to help diagnose and monitor these conditions.

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.

Tryptophan is an essential amino acid, meaning it cannot be synthesized by the human body and must be obtained through dietary sources. Its chemical formula is C11H12N2O2. Tryptophan plays a crucial role in various biological processes as it serves as a precursor to several important molecules, including serotonin, melatonin, and niacin (vitamin B3). Serotonin is a neurotransmitter involved in mood regulation, appetite control, and sleep-wake cycles, while melatonin is a hormone that regulates sleep-wake patterns. Niacin is essential for energy production and DNA repair.

Foods rich in tryptophan include turkey, chicken, fish, eggs, cheese, milk, nuts, seeds, and whole grains. In some cases, tryptophan supplementation may be recommended to help manage conditions related to serotonin imbalances, such as depression or insomnia, but this should only be done under the guidance of a healthcare professional due to potential side effects and interactions with other medications.

Aromatic amino acids are a specific type of amino acids that contain an aromatic ring in their side chain. The three aromatic amino acids are phenylalanine (Phe), tyrosine (Tyr), and tryptophan (Trp). These amino acids play important roles in various biological processes, including protein structure and function, neurotransmission, and enzyme catalysis.

The aromatic ring in these amino acids is composed of a planar six-membered carbon ring that contains alternating double bonds. This structure gives the side chains unique chemical properties, such as their ability to absorb ultraviolet light and participate in stacking interactions with other aromatic residues. These interactions can contribute to the stability and function of proteins and other biological molecules.

It's worth noting that while most amino acids are classified as either "hydrophobic" or "hydrophilic," depending on their chemical properties, aromatic amino acids exhibit characteristics of both groups. They can form hydrogen bonds with polar residues and also engage in hydrophobic interactions with nonpolar residues, making them versatile building blocks for protein structure and function.

Phenylalanine-tRNA ligase, also known as Phe-tRNA synthetase, is an enzyme that plays a crucial role in protein synthesis. Its primary function is to catalyze the attachment of the amino acid phenylalanine to its corresponding transfer RNA (tRNA) molecule. This reaction forms a phenylalanine-tRNA complex, which is then used in the translation process to create proteins according to the genetic code. The systematic name for this enzyme is phenylalanyl-tRNA synthetase (EC 6.1.1.20). Any defects or mutations in the Phe-tRNA ligase can lead to various medical conditions, including neurological disorders and impaired growth.

Phenylketonuria, Maternal is not a medical condition itself but rather a term that refers to the potential effects of maternal phenylketonuria (PKU) on the unborn child. PKU is a genetic disorder characterized by an inability to metabolize the amino acid phenylalanine, leading to its accumulation in the body and causing intellectual disability and other neurological problems if left untreated.

If a woman with PKU becomes pregnant and does not maintain a strict low-phenylalanine diet during pregnancy, the high levels of phenylalanine in her blood can lead to abnormal fetal development. The unborn child may develop congenital heart defects, microcephaly (abnormally small head), intrauterine growth retardation, and intellectual disability. This is known as maternal PKU syndrome or fetal PKU.

Therefore, it's crucial for women with PKU who are planning to become pregnant or are already pregnant to adhere strictly to a low-phenylalanine diet and monitor their blood phenylalanine levels regularly to minimize the risk of maternal PKU syndrome.

Fenclonine is not a commonly used medical term or a medication in clinical practice. It's possible that you may have encountered this term in the context of research or scientific studies. Fenclonine is an experimental drug that has been investigated for its potential role as an inhibitor of bacterial enzymes, specifically the D-alanine:D-alanine ligase (DD-transpeptidase) involved in bacterial cell wall biosynthesis.

Inhibiting this enzyme can disrupt the integrity and growth of bacteria, making fenclonine a potential antibiotic agent. However, further research is required to establish its safety, efficacy, and therapeutic applications. As such, it's not currently used as a standard treatment option in human medicine.

For accurate information regarding medical definitions or treatments, consult with healthcare professionals or refer to reputable medical resources.

P-Fluorophenylalanine (p-FPA) is not a medical term, but a chemical compound used in research and medical fields. It's a type of amino acid that is used as a building block for proteins, similar to the naturally occurring amino acid phenylalanine. However, p-FPA has a fluorine atom attached to its para position (one of the possible positions on the phenyl ring).

This compound can be used in various research applications, including the study of protein synthesis and enzyme function. It's also been explored as a potential therapeutic agent for certain medical conditions, such as cancer and neurological disorders. However, more research is needed to establish its safety and efficacy for these uses.

Chorismate mutase is an important enzyme in the biosynthetic pathway of aromatic amino acids in bacteria, fungi, and plants. This enzyme catalyzes the conversion of chorismate to prephenate, which is a key step in the synthesis of phenylalanine, tyrosine, and tryptophan.

The reaction catalyzed by chorismate mutase is as follows:

chorismate → prephenate

Inhibition of this enzyme has been explored as a potential target for the development of antibiotics and herbicides, as interrupting the synthesis of aromatic amino acids can be lethal to bacteria and plants. In humans, the equivalent reaction is catalyzed by a different set of enzymes, so chorismate mutase inhibitors are not expected to have toxic effects on human cells.

Site-directed mutagenesis is a molecular biology technique used to introduce specific and targeted changes to a specific DNA sequence. This process involves creating a new variant of a gene or a specific region of interest within a DNA molecule by introducing a planned, deliberate change, or mutation, at a predetermined site within the DNA sequence.

The methodology typically involves the use of molecular tools such as PCR (polymerase chain reaction), restriction enzymes, and/or ligases to introduce the desired mutation(s) into a plasmid or other vector containing the target DNA sequence. The resulting modified DNA molecule can then be used to transform host cells, allowing for the production of large quantities of the mutated gene or protein for further study.

Site-directed mutagenesis is a valuable tool in basic research, drug discovery, and biotechnology applications where specific changes to a DNA sequence are required to understand gene function, investigate protein structure/function relationships, or engineer novel biological properties into existing genes or proteins.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

Formyl peptide receptors (FPRs) are a type of G protein-coupled receptors that play a crucial role in the innate immune system. They are expressed on various cells including neutrophils, monocytes, and macrophages. FPRs recognize and respond to formylated peptides derived from bacteria, mitochondria, and host proteins during cell damage or stress. Activation of FPRs triggers a variety of cellular responses, such as chemotaxis, phagocytosis, and release of inflammatory mediators, which help to eliminate invading pathogens and promote tissue repair. There are three subtypes of human FPRs (FPR1, FPR2, and FPR3) that have distinct ligand specificities and functions in the immune response.

Chemotactic factors are substances that attract or repel cells, particularly immune cells, by stimulating directional movement in response to a chemical gradient. These factors play a crucial role in the body's immune response and inflammation process. They include:

1. Chemokines: A family of small signaling proteins that direct the migration of immune cells to sites of infection or tissue damage.
2. Cytokines: A broad category of signaling molecules that mediate and regulate immunity, inflammation, and hematopoiesis. Some cytokines can also act as chemotactic factors.
3. Complement components: Cleavage products of the complement system can attract immune cells to the site of infection or tissue injury.
4. Growth factors: Certain growth factors, like colony-stimulating factors (CSFs), can stimulate the migration and proliferation of specific cell types.
5. Lipid mediators: Products derived from arachidonic acid metabolism, such as leukotrienes and prostaglandins, can also act as chemotactic factors.
6. Formyl peptides: Bacterial-derived formylated peptides can attract and activate neutrophils during an infection.
7. Extracellular matrix (ECM) components: Fragments of ECM proteins, like collagen and fibronectin, can serve as chemotactic factors for immune cells.

These factors help orchestrate the immune response by guiding the movement of immune cells to specific locations in the body where they are needed.

Oligopeptides are defined in medicine and biochemistry as short chains of amino acids, typically containing fewer than 20 amino acid residues. These small peptides are important components in various biological processes, such as serving as signaling molecules, enzyme inhibitors, or structural elements in some proteins. They can be found naturally in foods and may also be synthesized for use in medical research and therapeutic applications.

N-Formylmethionine Leucyl-Phenylalanine at the U.S. National Library of Medicine Medical Subject Headings (MeSH) (CS1 errors: ... n-formylmethionine leucyl-phenylalanine, Cancerweb Panaro MA, Mitolo V (Aug 1999). "Cellular responses to fMLF challenging: a ... N-Formylmethionyl-leucyl-phenylalanine (fMLF, fMLP or N-formyl-met-leu-phe) is an N-formylated tripeptide and sometimes simply ... 1978). "Molecular events in the response of neutrophils to synthetic N-formylmethionine chemotactic peptides.". In J. A. Gallin ...
N-formylmethionine-leucyl-phenylalanine); b) complement components C5a and C3a which are chemotactic factors formed during the ...
... oligopeptides such as N-Formylmethionine-leucyl-phenylalanine; and various proteins such as the amino acid 1 to 42 fragment of ... N-Formylmethionine-leucyl-phenylalanine (http://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=223}. Activation ...
... possess an N-Formylmethionine N-terminal residue such as the prototypical tripeptide N-Formylmethionine-leucyl-phenylalanine (i ... ligands including not only certain N-Formylmethionine-containing oligopeptides such as N-Formylmethionine-leucyl-phenylalanine ...
... and N-Formylmethionine leucyl-phenylalanine and other N-formylated oligopeptides which are made by bacteria and activate the ...
Formyl peptide receptor 1 Formyl peptide receptor 2 N-Formylmethionine-leucyl-phenylalanine GRCh38: Ensembl release 89: ...
N-Formylmethionine-leucyl-phenylalanine (FMLP or fMet-Leu-Phe), stimulated rabbit and human neutrophils by an apparent receptor ... particularly N-Formylmethionine-leucyl-phenylalanine (FMLP). FPR1 is prominently expressed by mammalian phagocytic and blood ... or N-formylmethionyl-leucyl-phenylalanine receptor 1) is a cell surface receptor protein that in humans is encoded by the ... This gene encodes a G protein-coupled receptor cell surface protein that binds and is activated by N-Formylmethionine- ...
... including N-formylmethionine-leucyl-phenylalanine, fMLP). The correlation between the early stages of cell death and the ...
... myosin N-formylmethionine - N-formylmethionine leucyl-phenylalanine - N-methyl-D-aspartate receptor - N-methylaspartate - N- ... phenylalanine - Philadelphia chromosome - phospholipid - phospholipid bilayer - phosphopeptide - phosphoprotein - phosphorus - ...
N-formylmethionine-leucyl-phenylalanine (FMLP), based on its amino acid sequence similarity to the known FMLP receptor, FPR1. ...
... n-formylmethionine MeSH D12.125.166.676.450.440 - n-formylmethionine leucyl-phenylalanine MeSH D12.125.166.676.620 - methionine ... phenylalanine MeSH D12.125.142.815 - threonine MeSH D12.125.142.875 - tryptophan MeSH D12.125.142.930 - valine MeSH D12.125. ... phenylalanine MeSH D12.125.072.050.685.400 - dihydroxyphenylalanine MeSH D12.125.072.050.685.400.180 - cysteinyldopa MeSH ...
N-Formylmethionine-leucyl-phenylalanine, that are made by a variety of replicating gram positive bacteria and gram negative ...
... n-formylmethionine MeSH D02.886.030.676.450.440 - n-formylmethionine leucyl-phenylalanine MeSH D02.886.030.676.620 - methionine ...
... which is a receptor for N-Formylmethionine-leucyl-phenylalanine and related N-formyl peptide chemotactic factors, and 35% ...
N-formylmethionine-leucyl-phenylalanine (fMLF or fMet-Leu-Phe), stimulated rabbit and human neutrophils by an apparent receptor ... These receptors were originally identified by their ability to bind N-formyl peptides such as N-formylmethionine produced by ... Studies conducted in the 1970s found that a series of N-Formylmethionine-containing oligopeptides, including the most potent ...
... n-formylmethionine leucyl-phenylalanine MeSH D23.348.353.100 - cyclin a MeSH D23.348.353.120 - cyclin b MeSH D23.348.353.161 - ...
The prototypical fMet-containing oligopeptide is N-formylmethionine-leucyl-phenylalanine (FMLP) which activates leukocytes and ... N-Formylmethionine (fMet, HCO-Met, For-Met) is a derivative of the amino acid methionine in which a formyl group has been added ... N-Formylmethionine at the U.S. National Library of Medicine Medical Subject Headings (MeSH) (CS1 maint: location missing ...
... n-formylmethionine leucyl-phenylalanine MeSH D12.644.456.448 - glutathione MeSH D12.644.456.448.500 - glutathione disulfide ...
A complicating issue is that the first residue of bacterial proteins is normally expressed with an N-terminal formylmethionine ... This study revealed that Phenylalanine and Tryptophan bind specifically to ClpS1, making them prime candidates for N-degrons in ... Secondary destabilising residues are modified by the attachment of a Primary destabilising residue by the enzyme leucyl/ ... In bacteria, destabilising residues can be further defined as Primary destabilising residues (leucine, phenylalanine, tyrosine ...
N-Formylmethionine Leucyl-Phenylalanine at the U.S. National Library of Medicine Medical Subject Headings (MeSH) (CS1 errors: ... n-formylmethionine leucyl-phenylalanine, Cancerweb Panaro MA, Mitolo V (Aug 1999). "Cellular responses to fMLF challenging: a ... N-Formylmethionyl-leucyl-phenylalanine (fMLF, fMLP or N-formyl-met-leu-phe) is an N-formylated tripeptide and sometimes simply ... 1978). "Molecular events in the response of neutrophils to synthetic N-formylmethionine chemotactic peptides.". In J. A. Gallin ...
N-Formylmethionine Leucyl-Phenylalanine / pharmacology* * Neutrophils / drug effects * Neutrophils / physiology* * Platelet ... N-formyl-methionyl-leucyl-phenylalanine (FMLP), or leukotriene B4 (LTB4). Platelets alone aggregated and showed intracellular ...
... coated glass coverslips before and after stimulation with the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine ... N-Formylmethionine Leucyl-Phenylalanine * Neutrophils/cytology/ physiology account_balance. Affiliation. * Faculté de médecine ...
N-Formylmethionine Leucyl-Phenylalanine/pharmacology. MESH. NADH, NADPH Oxidoreductases/blood. MESH. NADPH Oxidase. MESH. ... Whereas the chemotactic peptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe), induced NADPH-oxidase-catalyzed ... Whereas the chemotactic peptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe), induced NADPH-oxidase-catalyzed ...
... and the GPCR recognizing N-Formylmethionine-leucyl-phenylalanine (fMLP) result in direct activation of NOX2 (Nguyen et al., ...
N-Formylmethionine Leucyl-Phenylalanine. *Macrophage Colony-Stimulating Factor. *Humans. *Granulocytes. *Granulocyte-Macrophage ... increase in F-actin content after stimulation with either the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP ...
N-Formylmethionine Leucyl-Phenylalanine Medicine & Life Sciences 75% * Endothelium Medicine & Life Sciences 60% ... under control conditions and following tissue suffusion with the chemotactic agent N-formyl-methionyl-leucyl-phenylalanine ( ... under control conditions and following tissue suffusion with the chemotactic agent N-formyl-methionyl-leucyl-phenylalanine ( ... under control conditions and following tissue suffusion with the chemotactic agent N-formyl-methionyl-leucyl-phenylalanine ( ...
N-Formylmethionine Leucyl-Phenylalanine * Phosphorylation * Receptors, Formyl Peptide * Receptors, Immunologic * Receptors, ...
N-Formylmethionine Leucyl-Phenylalanine, Neutrophils, Oxygen, Peroxidase",. author = "Treweeke, {A T} and Aziz, {K A} and M ... We found that chemiluminescence (CL) stimulated by formylmethionyl-leucyl-phenylalanine (fMLP) was not influenced by G-CSF (0.1 ... We found that chemiluminescence (CL) stimulated by formylmethionyl-leucyl-phenylalanine (fMLP) was not influenced by G-CSF (0.1 ... We found that chemiluminescence (CL) stimulated by formylmethionyl-leucyl-phenylalanine (fMLP) was not influenced by G-CSF (0.1 ...
N-Formylmethionine Leucyl-Phenylalanine 28% * Transendothelial and Transepithelial Migration 27% * Chemotaxis 22% ...
... leucyl-phenylalanine, whereas lung leak was assessed by 125I-albumin lung/blood ratio. In sum, CD11b blockade prevented gut I/R ... leucyl-phenylalanine, whereas lung leak was assessed by 125I-albumin lung/blood ratio. In sum, CD11b blockade prevented gut I/R ... leucyl-phenylalanine, whereas lung leak was assessed by 125I-albumin lung/blood ratio. In sum, CD11b blockade prevented gut I/R ... leucyl-phenylalanine, whereas lung leak was assessed by 125I-albumin lung/blood ratio. In sum, CD11b blockade prevented gut I/R ...
... methylation of Ras-related proteins increased in response to the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP ... methylation of Ras-related proteins increased in response to the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP ... methylation of Ras-related proteins increased in response to the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP ... methylation of Ras-related proteins increased in response to the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP ...
N-Formylmethionine Leucyl-Phenylalanine. *Netropsin. *Pentagastrin. *Pepstatins. *Peptichemio. *Peptide T. *Phalloidine. * ...
N-Formylmethionine-Leucyl-Phenylalanine; Normal distribution; Partial differential equation; Sammanfattning : The leukocytes ...
... that was originally identified by its ability to bind N-formyl peptides such as N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE. Since ...
The prototypical fMet-containing oligopeptide is N-formylmethionine-leucyl-phenylalanine (FMLP) which activates leukocytes and ... N-Formylmethionine (fMet,[2] HCO-Met,[3] For-Met[3]) is a derivative of the amino acid methionine in which a formyl group has ... N-Formylmethionine (data page) Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 ... N-Formylmethionine at the U.S. National Library of Medicine Medical Subject Headings (MeSH) ...
N-Formylmethionine Leucyl-Phenylalanine D23.125.320.685 D12.125.72.50.685.445 D12.125.142.666.500 Nairobi sheep disease virus ...
N-Formylmethionine Leucyl-Phenylalanine D23.125.320.685 D12.125.72.50.685.445 D12.125.142.666.500 Nairobi sheep disease virus ...
N-Formylmethionine Leucyl-Phenylalanine D23.125.320.685 D12.125.72.50.685.445 D12.125.142.666.500 Nairobi sheep disease virus ...
N-formylmethionine-leucyl-phenylalanine), and anti-FcεRI). We measured avidin binding and CD63 expression on basophils with ...
N-Formylmethionine Leucyl-Phenylalanine D23.125.320.685 D12.125.72.50.685.445 D12.125.142.666.500 Nairobi sheep disease virus ...
N-Formylmethionine Leucyl-Phenylalanine D23.125.320.685 D12.125.72.50.685.445 D12.125.142.666.500 Nairobi sheep disease virus ...
Aspect Receptor ER Endoplasmic Reticulum FAD Flavin Adenine Dinucleotide fMLP N-Formyl-Methionine-Leucyl-Phenylalanine G-MDSC ...
N-Formylmethionine Leucyl-Phenylalanine:pharmacology, Neutrophils:drug effects, Oxidants:metabolism. Citation OBJECTIVES: To ... N-Formylmethionine Leucyl-Phenylalanine:pharmacology, Nitric Oxide Synthase Type II:metabolism, Peroxidase:m. Citation ...
N-Formylmethionine Leucyl-Phenylalanine. *Netropsin. *Pentagastrin. *Pepstatins. *Peptichemio. *Peptide T. *Phalloidine. * ...
N-Formylmethionine Leucyl-Phenylalanine. * Okadaic Acid. * Phospholipases A. * Protein Kinase C. * Protons ...
N-Formylmethionine Leucyl-Phenylalanine. *Netrins. *Cytokines. *Chemokines. *Growth Differentiation Factor 15. *Hematopoietic ...
N-Formylmethionine Leucyl-Phenylalanine [D12.644.456.400] * Glutathione [D12.644.456.448] * Gonadotropin-Releasing Hormone [ ...
N Formylmethionine Leucyl Phenylalanine use N-Formylmethionine Leucyl-Phenylalanine N formylmethionyl leucyl phenylalanine use ... N Formyl Methionyl Leucyl Phenylalanine use N-Formylmethionine Leucyl-Phenylalanine N Formylated Peptide use N-Formylmethionine ... N-Formyl-Methionyl-Leucyl-Phenylalanine use N-Formylmethionine Leucyl-Phenylalanine N-Formylated Peptide use N-Formylmethionine ... N-formylmethionyl-leucyl-phenylalanine use N-Formylmethionine Leucyl-Phenylalanine N-Glycanase use Peptide-N4-(N-acetyl-beta- ...
  • N-Formylmethionyl-leucyl-phenylalanine (fMLF, fMLP or N-formyl-met-leu-phe) is an N-formylated tripeptide and sometimes simply referred to as chemotactic peptide is a potent polymorphonuclear leukocyte (PMN) chemotactic factor and is also a macrophage activator. (wikipedia.org)
  • Cells were exposed to one of three chemotactic stimuli: platelet-activating factor (PAF), N-formyl-methionyl-leucyl-phenylalanine (FMLP), or leukotriene B4 (LTB4). (nih.gov)
  • To study the role of adhesion in cell activation, we monitored [Ca2+]i in single neutrophils adhered to albumin-coated or fibronectin-coated glass coverslips before and after stimulation with the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP). (unige.ch)
  • Although the basal level of F-actin was high following ABMT, granulocytes from all patients showed an additional increase in F-actin content after stimulation with either the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) or phorbol myristate acetate (PMA). (duke.edu)
  • The effects of leukocyte-endothelium adhesion on microhemodynamics were studied in cat mesentery under control conditions and following tissue suffusion with the chemotactic agent N-formyl-methionyl-leucyl-phenylalanine (FMLP). (psu.edu)
  • We found that chemiluminescence (CL) stimulated by formylmethionyl-leucyl-phenylalanine (fMLP) was not influenced by G-CSF (0.1-100 ng/ml), whereas GM-CSF priming (10 ng/ml) caused a nearly twofold increase in this PMN response. (uhi.ac.uk)
  • In intact cells and in a reconstituted in vitro system, the amount of carboxyl methylation of Ras-related proteins increased in response to the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (FMLP). (princeton.edu)
  • The prototypical fMet-containing oligopeptide is N -formylmethionine-leucyl-phenylalanine (FMLP) which activates leukocytes and other cell types by binding with these cells' formyl peptide receptor 1 (FPR1) and formyl peptide receptor 2 (FPR2) G protein coupled receptors (see also formyl peptide receptor 3 ). (wikipedia.org)
  • We conducted BATs in response to seven peanut extract (PE) concentrations (0.01-10,000 ng/mL) and four control conditions (no stimulant, anti-IgE, fMLP (N-formylmethionine-leucyl-phenylalanine), and anti-FcεRI). (bvsalud.org)
  • Given these clues and knowledge that bacteria transcribe (see Transcription (genetics)) proteins starting with N-formylmethionine whereas eukaryotic cells mostly initiate protein synthesis with non-formylated methionine, Schiffmann, Corcoran, and Wahl theorized and then showed that N-formyl-methionine and a series N-formyl-methionyl dipeptides and tripeptides stimulated the chemotaxis of neutrophils isolated from rabbit peritoneal exudates as well as of macrophages isolated from guinea pig peritoneal exudates. (wikipedia.org)
  • Whereas the chemotactic peptide, N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe), induced NADPH-oxidase-catalyzed superoxide (O2-) formation in human neutrophils, purine and pyrimidine nucleotides per se did not stimulate NADPH oxidase but enhanced O2- formation induced by submaximally and maximally stimulatory concentrations of fMet-Leu-Phe up to fivefold. (uni-regensburg.de)
  • Given these clues and knowledge that bacteria transcribe (see Transcription (genetics)) proteins starting with N-formylmethionine whereas eukaryotic cells mostly initiate protein synthesis with non-formylated methionine, Schiffmann, Corcoran, and Wahl theorized and then showed that N-formyl-methionine and a series N-formyl-methionyl dipeptides and tripeptides stimulated the chemotaxis of neutrophils isolated from rabbit peritoneal exudates as well as of macrophages isolated from guinea pig peritoneal exudates. (wikipedia.org)
  • The researchers then exposed the neutrophils to both 6-gingerol and the peptide N-formylmethionine-leucyl-phenylalanine [fMLF]. (ergo-log.com)
  • Exposure to N-formylmethionine-leucyl-phenylalanine caused the neutrophils to produce more CXCL8. (ergo-log.com)
  • A family of G-protein-coupled receptors that was originally identified by its ability to bind N-formyl peptides such as N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE. (harvard.edu)