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Proprotein Convertase 2
Proprotein convertase 2 (PC2) also known as prohormone convertase 2 or neuroendocrine convertase 2 (NEC2) is a serine protease and proprotein convertase PC2, like proprotein convertase 1 (PC1), is an enzyme responsible for the first step in the maturation of many neuroendocrine peptides from their precursors, such as the conversion of proinsulin to insulin intermediates. To generate the bioactive form of insulin (and many other peptides), a second step involving the removal of C-terminal basic residues is required; this step is mediated by carboxypeptidases E and/or D. PC2 plays only a minor role in the first step of insulin biosynthesis, but a greater role in the first step of glucagon biosynthesis compared to PC1. PC2 binds to the neuroendocrine protein named 7B2, and if this protein is not present, proPC2 cannot become enzymatically active. 7B2 accomplishes this by preventing the aggregation of proPC2 to inactivatable forms. The C-terminal domain of 7B2 also inhibits PC2 act ... [...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] |
Proprotein Convertase
Proprotein convertases (PPCs) are a family of proteins that activate other proteins. Many proteins are inactive when they are first synthesized, because they contain chains of amino acids that block their activity. Proprotein convertases remove those chains and activate the protein. The prototypical proprotein convertase is furin. Proprotein convertases have medical significance, because they are involved in many important biological processes, such as cholesterol synthesis. Compounds called proprotein convertase inhibitors can block their action, and block the target proteins from becoming active. Many proprotein convertases, especially furin and PACE4, are involved in pathological processes such as viral infection, inflammation, hypercholesterolemia, and cancer, and have been postulated as therapeutic targets for some of these diseases. History The phenomenon of prohormone conversion was discovered by Donald F. Steiner while examining the biosynthesis of insulin in 1967. At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proprotein Convertase 1
Proprotein convertase 1, also known as prohormone convertase, prohormone convertase 3, or neuroendocrine convertase 1 and often abbreviated as PC1/3 is an enzyme that in humans is encoded by the ''PCSK1'' gene. PCSK1 and PCSK2 differentially cleave proopiomelanocortin and they act together to process proinsulin and proglucagon in pancreatic islets. Function PC1/3 is an enzyme that performs the proteolytic cleavage of prohormones to their intermediate (or sometimes completely cleaved) forms. It is present only in neuroendocrine cells such as brain, pituitary and adrenal, and most often cleaves after a pair of basic residues within prohormones but can occasionally cleave after a single arginine. It binds to a protein known as proSAAS, which also represents its endogenous inhibitor. PC1 is synthesized as a 99 kDa proform quickly converted to an 87 kDa major active form, which itself is nearly completely cleaved to a 66 kDa active form within neuroendocrine cells. Proprotein con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proinsulin
Proinsulin is the prohormone precursor to insulin made in the beta cells of the Pancreatic Islets, specialized regions of the pancreas. In humans, proinsulin is encoded by the ''INS'' gene. The pancreatic islets only secrete between 1% and 3% of proinsulin intact. However, because proinsulin has a longer half life than insulin, it can account for anywhere from 5–30% of the insulin-like structures circulating in the blood. There are higher concentrations of proinsulin after meals and lower levels when a person is fasting. Additionally, while proinsulin and insulin have structural differences, proinsulin does demonstrate some affinity for the insulin receptor. Due to the relative similarities in structure, proinsulin can produce between 5% and 10% of the metabolic activity similarly induced by insulin. Proinsulin is the final single chain protein structure secreted by cells before cleavage into mature insulin. Proinsulin was discovered by Professor Donald F. Steiner of the Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (''INS)'' gene. It is the main Anabolism, anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats, and protein by promoting the absorption of glucose from the blood into cells of the liver, fat cell, fat, and skeletal muscles. In these tissues the absorbed glucose is converted into either glycogen, via glycogenesis, or Fatty acid metabolism#Glycolytic end products are used in the conversion of carbohydrates into fatty acids, fats (triglycerides), via lipogenesis; in the liver, glucose is converted into both. Glucose production and secretion by the liver are strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is thus an anabolic hormone, promoting the conversion of small molecules in the blood into large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-terminal
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, carboxy tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus. Chemistry Each amino acid has a carboxyl group and an amine group. Amino acids link to one another to form a chain by a dehydration reaction which joins the amine group of one amino acid to the carboxyl group of the next. Thus polypeptide chains have an end with an unbound carboxyl group, the C-terminus, and an end with an unbound amine group, the N-terminus. Proteins are naturally synthesized starting from the N-terminus and ending at the C-terminus. Function C-terminal retention signals While the N-terminus of a prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon
Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It raises the concentration of glucose and fatty acids in the bloodstream and is considered to be the main catabolic hormone of the body. It is also used as a Glucagon (medication), medication to treat a number of health conditions. Its effect is opposite to that of insulin, which lowers extracellular glucose. It is produced from proglucagon, encoded by the ''GCG'' gene. The pancreas releases glucagon when the amount of glucose in the bloodstream is too low. Glucagon causes the liver to engage in glycogenolysis: converting stored glycogen into glucose, which is released into the bloodstream. High blood-glucose levels, on the other hand, stimulate the release of insulin. Insulin allows glucose to be taken up and used by insulin-dependent tissues. Thus, glucagon and insulin are part of a feedback system that keeps blood glucose levels stable. Glucagon increases energy expenditure and is elevated under conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCSK6
Proprotein convertase subtilisin/kexin type 6 is an protease that in humans is encoded by the ''PCSK6'' gene which is located in chromosome 15. Pcsk6 is a calcium-dependent serine endoprotease that catalyzes the post-translational modification of precursor proteins from its ‘latent’ form to the cleaved ‘active’ form. Active Pcsk6 has been reported to process substrates such as transforming growth factor β, pro-albumin, von Willebrand factor, and corin. Clinically, Pcsk6 is suggested to play a role in left/right asymmetry, structural asymmetry of the brain, handedness, tumor progression, hemostasis, and cardiovascular diseases. Function The protein encoded by this gene belongs to the subtilisin-like proprotein convertase family. The members of this family are proprotein convertases that process latent precursor proteins into their biologically active products. This encoded protein is a calcium-dependent serine endoprotease that can cleave precursor protein at their pair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCSK4
Proprotein convertase subtilisin/kexin type 4 is an enzyme that in humans is encoded by the ''PCSK4'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei .... References Further reading * * * * * * * * * * * {{gene-19-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
