An antineoplastic agent derived from BLEOMYCIN.
Databases containing information about PROTEINS such as AMINO ACID SEQUENCE; PROTEIN CONFORMATION; and other properties.
A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.
The portion of an interactive computer program that issues messages to and receives commands from a user.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Ubiquitous macromolecules associated with the cell surface and extracellular matrix of a wide range of cells of vertebrate and invertebrate tissues. They are essential cofactors in cell-matrix adhesion processes, in cell-cell recognition systems, and in receptor-growth factor interactions. (From Cancer Metastasis Rev 1996; 15(2): 177-86; Hepatology 1996; 24(3): 524-32)
A polypeptide antibiotic mixture obtained from Bacillus brevis. It consists of a mixture of three tyrocidines (60%) and several gramicidins (20%) and is very toxic to blood, liver, kidneys, meninges, and the olfactory apparatus. It is used topically.
A heteropolysaccharide that is similar in structure to HEPARIN. It accumulates in individuals with MUCOPOLYSACCHARIDOSIS.
Glycoproteins which have a very high polysaccharide content.
A fibrous protein complex that consists of proteins folded into a specific cross beta-pleated sheet structure. This fibrillar structure has been found as an alternative folding pattern for a variety of functional proteins. Deposits of amyloid in the form of AMYLOID PLAQUES are associated with a variety of degenerative diseases. The amyloid structure has also been found in a number of functional proteins that are unrelated to disease.
Proteoglycans consisting of proteins linked to one or more CHONDROITIN SULFATE-containing oligosaccharide chains.
A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.
A myelin protein that is the major component of the organic solvent extractable lipoprotein complexes of whole brain. It has been the subject of much study because of its unusual physical properties. It remains soluble in chloroform even after essentially all of its bound lipids have been removed. (From Siegel et al., Basic Neurochemistry, 4th ed, p122)
The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem.
A villous structure of tangled masses of BLOOD VESSELS contained within the third, lateral, and fourth ventricles of the BRAIN. It regulates part of the production and composition of CEREBROSPINAL FLUID.
MYELIN-specific proteins that play a structural or regulatory role in the genesis and maintenance of the lamellar MYELIN SHEATH structure.
The thermodynamic interaction between a substance and WATER.
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 poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds.
A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).
A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured. Such rupture is supposed to be under metabolic (hormonal) control. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
An abundant lysosomal-associated membrane protein that has been found to shuttle between LYSOSOMES; ENDOSOMES; and the PLASMA MEMBRANE. Loss of expression of lysosomal-associated membrane protein 2 is associated with GLYCOGEN STORAGE DISEASE TYPE IIB.
Disorders caused by imbalances in the protein homeostasis network - synthesis, folding, and transport of proteins; post-translational modifications; and degradation or clearance of misfolded proteins.
A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.
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.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
Heat and stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria of the genera Bacillus and Clostridium.
A species of gram-positive bacteria that is a common soil and water saprophyte.
Proteins found in any species of bacterium.
The reproductive elements of lower organisms, such as BACTERIA; FUNGI; and cryptogamic plants.
A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.
A republic in western Africa, south of GUINEA and west of LIBERIA. Its capital is Freetown.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.
A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.
A type of FLUORESCENCE SPECTROSCOPY using two FLUORESCENT DYES with overlapping emission and absorption spectra, which is used to indicate proximity of labeled molecules. This technique is useful for studying interactions of molecules and PROTEIN FOLDING.
The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.
Measurement of the intensity and quality of fluorescence.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.