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Angiostatin
Angiostatin is a naturally occurring protein found in several animal species, including humans. It is an endogenous angiogenesis inhibitor (i.e., it blocks the growth of new blood vessels). Clinical trials have been undertaken for its use in anticancer therapy. Structure Angiostatin is a 38 kDa fragment of a larger protein, plasmin (itself a fragment of plasminogen) enclosing three to five contiguous kringle modules. Each module contains two small beta sheets and three disulfide bonds. There are four different structural variants to angiostatin differing in the combination of kringle domains: K1-3, K1-4, K1-5, K1-4 with a fragment of K-5. Each kringle domain contributes a different element of inhibition to the cytokine. Recent studies through recombinant angiostatin have shown however that K1-3 is pivotal is the inhibitory nature of angiostatin. K1-3 form the “triangular bowl-like structure” of angiostatin. This structure is stabilized by interactions between inter-kringle p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiomotin
Angiomotin (AMOT) is a protein that in humans is encoded by the ''AMOT'' gene. It belongs to the motin family of angiostatin binding proteins, which includes angiomotin, angiomotin-like 1 ( AMOTL1) and angiomotin-like 2 (AMOTL2) characterized by coiled-coil domains at N-terminus and consensus PDZ-binding domain at the C-terminus. Angiomotin is expressed predominantly in endothelial cells of capillaries as well as angiogenic tissues such as placenta and solid tumor. Discovery Angiomotin was discovered in 2001 by screening a placenta yeast two-hybrid cDNA library for angiostatin-binding peptides, using a construct encoding the kringle domains 1-4 of angiostatin. Gene location ''AMOT'' gene is located on human chromosome X:112,021,794-112,066,354, containing 3252 nucleotides in coding sequence as 11 exons. Protein structure Two splice isoforms are known for angiomotin: p80 and p130. The alternative splicing is somewhat tissue specific. Cells expressing p130 contained more ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biology), morphology) and death. These changes include Bleb (cell biology), blebbing, Plasmolysis, cell shrinkage, Karyorrhexis, nuclear fragmentation, Pyknosis, chromatin condensation, Apoptotic DNA fragmentation, DNA fragmentation, and mRNA decay. The average adult human loses 50 to 70 1,000,000,000, billion cells each day due to apoptosis. For the average human child between 8 and 14 years old, each day the approximate loss is 20 to 30 billion cells. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Growth
Cell most often refers to: * Cell (biology), the functional basic unit of life * Cellphone, a phone connected to a cellular network * Clandestine cell, a penetration-resistant form of a secret or outlawed organization * Electrochemical cell, a device used to convert chemical energy to electrical energy * Prison cell, a room used to hold people in prisons Cell may also refer to: Arts, entertainment, and media Fictional entities * Cell (comics), a Marvel comic book character * Cell (Dragon Ball), Cell (''Dragon Ball''), a character in the manga series ''Dragon Ball'' Literature * Cell (novel), ''Cell'' (novel), a 2006 horror novel by Stephen King * "Cells", poem, about a hungover soldier in gaol, by Rudyard Kipling *The Cell (play), ''The Cell'' (play), an Australian play by Robert Wales Music * Cell (music), a small rhythmic and melodic design that can be isolated, or can make up one part of a thematic context * Cell (American band) * Cell (Japanese band) * Cell (album), ''Cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NG2 Proteoglycan
Neural/glial antigen 2, or NG2, is a rat integral membrane proteoglycan found in the plasma membrane of many diverse cell types.Nishiyama A, Dahlin KJ, Prince JT, Johnstone SR, Stallcup WB. "The primary structure of NG2: a novel membrane-spanning proteoglycan." ''J Cell Biol''. 1991 Jul;114(2):359-71. . Homologous proteins in other species include human CSPG4, also known as melanoma-associated chondroitin sulfate proteoglycan (MCSP), Mouse AN2, and Sea urchin ECM3.Asher RA, Morgenstern DA, Fawcett JW. "Chondroitin sulphate proteoglycans: inhibitory components of the glial scar." Prog Brain Res. 2001;132:611-9. . This single-pass transmembrane molecule may be plasma membrane-bound or secreted and associated with the extracellular matrix.Nishiyama A, Lin ZH, Stallcup WB. "Generation of truncated forms of the NG2 proteoglycan by cell surface proteolysis." ''Mol Biol Cell''. 1995 Dec;6(12):1819-32. It is believed to play a role in functions such as cell adhesion, cell-cell and cell-ECM c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annexin
Annexin is a common name for a group of cellular proteins. They are mostly found in eukaryotic organisms (animals, plants and fungi). In humans, the annexins are found inside the cell. However some annexins (Annexin A1, Annexin A2, and Annexin A5) can be secreted from the cytoplasm to outside cellular environments, such as blood. Annexin is also known as ''lipocortin''. Lipocortins suppress phospholipase A2. Increased expression of the gene coding for annexin-1 is one of the mechanisms by which glucocorticoids (such as cortisol) inhibit inflammation. Introduction The protein family of annexins has continued to grow since their association with intracellular membranes was first reported in 1977. The recognition that these proteins were members of a broad family first came from protein sequence comparisons and their cross-reactivity with antibodies. One of these workers (Geisow) coined the name Annexin shortly after. As of 2002 160 annexin proteins have been identified in 65 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrin
Integrins are transmembrane receptors that help cell–cell and cell–extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, organization of the intracellular cytoskeleton, and movement of new receptors to the cell membrane. The presence of integrins allows rapid and flexible responses to events at the cell surface (''e.g''. signal platelets to initiate an interaction with coagulation factors). Several types of integrins exist, and one cell generally has multiple different types on its surface. Integrins are found in all animals while integrin-like receptors are found in plant cells. Integrins work alongside other proteins such as cadherins, the immunoglobulin superfamily cell adhesion molecules, selectins and syndecans, to mediate cell–cell and cell–matrix interaction. Ligands for integrins include fibronectin, vitronectin, collagen and laminin. Stru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATP Synthase
ATP synthase is an enzyme that catalyzes the formation of the energy storage molecule adenosine triphosphate (ATP) using adenosine diphosphate (ADP) and inorganic phosphate (Pi). ATP synthase is a molecular machine. The overall reaction catalyzed by ATP synthase is: * ADP + Pi + 2H+out ATP + H2O + 2H+in ATP synthase lies across a cellular membrane and forms an aperture that hydron (chemistry), protons can cross from areas of high concentration to areas of low concentration, imparting energy for the synthesis of ATP. This electrochemical gradient is generated by the electron transport chain and allows cells to store energy in ATP for later use. In prokaryote, prokaryotic cells ATP synthase lies across the plasma membrane, while in eukaryote, eukaryotic cells it lies across the inner mitochondrial membrane. Organisms capable of photosynthesis also have ATP synthase across the thylakoid membrane, which in plants is located in the chloroplast and in cyanobacteria is located in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endopeptidase
Endopeptidase or endoproteinase are proteolytic peptidases that break peptide bonds of nonterminal amino acids (i.e. within the molecule), in contrast to exopeptidases, which break peptide bonds from end-pieces of terminal amino acids. For this reason, endopeptidases cannot break down peptides into monomers, while exopeptidases can break down proteins into monomers. A particular case of endopeptidase is the oligopeptidase, whose substrates are oligopeptides instead of proteins. They are usually very specific for certain amino acids. Examples of endopeptidases include: * Trypsin - cuts after Arg or Lys, unless followed by Pro. Very strict. Works best at pH 8. * Chymotrypsin - cuts after Phe, Trp, or Tyr, unless followed by Pro. Cuts more slowly after His, Met or Leu. Works best at pH 8. * Elastase - cuts after Ala, Gly, Ser, or Val, unless followed by Pro. * Thermolysin - cuts ''before'' Ile, Met, Phe, Trp, Tyr, or Val, unless ''preceded'' by Pro. Sometimes cuts after Ala, Asp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serine Protease
Serine proteases (or serine endopeptidases) are enzymes that cleave peptide bonds in proteins. Serine serves as the nucleophilic amino acid at the (enzyme's) active site. They are found ubiquitously in both eukaryotes and prokaryotes. Serine proteases fall into two broad categories based on their structure: chymotrypsin-like (trypsin-like) or subtilisin-like. Classification The MEROPS protease classification system counts 16 protein superfamily, superfamilies (as of 2013) each containing many protein family, families. Each superfamily uses the catalytic triad or dyad in a different protein fold and so represent convergent evolution of the catalytic mechanism. The majority belong to the S1 family of the PA clan (superfamily) of proteases. For protein superfamily, superfamilies, P: superfamily, containing a mixture of nucleophile class families, S: purely serine proteases. superfamily. Within each superfamily, protein family, families are designated by their catalytic nucl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastase
In molecular biology, elastase is an enzyme from the class of proteases (peptidases) that break down proteins, specifically one that can break down elastin. In other words, the name only refers to the substrate specificity (i.e. what proteins it can digest), not to any kind of evolutionary grouping. Forms and classification Eight human genes exist for elastase: The four "pancreatic elastases", chymotrypsin, and neutrophil elastase are serine proteases. The "macrophage elastase" is a matrix metallopeptidase. Chymotrypsin is weaker at digesting elastin than the architypical pancreatic elastase. Some bacteria (including ''Pseudomonas aeruginosa'') also produce elastase; bacterial elestases work in many ways and include serine proteases, aspartic proteases, thiol proteases, and metalloenzymes. Function The fact that elastase can break down elastin in test tubes (while other proteases cannot) does not imply that there is a unifying function for all elastases in the living ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
