Collagen is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole-body protein content. Collagen consists of amino acids bound together to form a triple helix of elongated fibril known as a collagen helix. It is mostly found in connective tissue such as cartilage, bones, tendons, ligaments, and skin. Vitamin C is vital for collagen synthesis, and Vitamin E improves the production of collagen.
Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group -NH
2 but is rather a secondary amine. The secondary amine nitrogen is in the protonated form (NH2+) under biological conditions, while the carboxyl group is in the deprotonated −COO− form. The "side chain" from the α carbon connects to the nitrogen forming a pyrrolidine loop, classifying it as a aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it from the non-essential amino acid L-glutamate. It is encoded by all the codons starting with CC (CCU, CCC, CCA, and CCG).
(2S,4R)-4-Hydroxyproline, or L-hydroxyproline (C5H9O3N), is an amino acid, abbreviated as Hyp or O, e.g., in Protein Data Bank.
In chemistry, hydroxylation can refer to:
Matrix metalloproteinases (MMPs), also known as matrix metallopeptidases or matrixins, are metalloproteinases that are calcium-dependent zinc-containing endopeptidases; other family members are adamalysins, serralysins, and astacins. The MMPs belong to a larger family of proteases known as the metzincin superfamily.
Serine proteases 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.
β-Glucuronidases are members of the glycosidase family of enzymes that catalyze breakdown of complex carbohydrates. Human β-glucuronidase is a type of glucuronidase that catalyzes hydrolysis of β-D-glucuronic acid residues from the non-reducing end of mucopolysaccharides such as heparan sulfate. Human β-glucuronidase is located in the lysosome. In the gut, brush border β-glucuronidase converts conjugated bilirubin to the unconjugated form for reabsorption. β-Glucuronidase is also present in breast milk, which contributes to neonatal jaundice. The protein is encoded by the GUSB gene in humans and by the uidA gene in bacteria.
Carnitine palmitoyltransferase II deficiency, sometimes shortened to CPT-II or CPT2, is an autosomal recessively inherited genetic metabolic disorder characterized by an enzymatic defect that prevents long-chain fatty acids from being transported into the mitochondria for utilization as an energy source. The disorder presents in one of three clinical forms: lethal neonatal, severe infantile hepatocardiomuscular and myopathic.
Gelatinases are enzymes capable of degrading gelatin through hydrolysis, playing a major role in degradation of extracellular matrix and tissue remodeling. Gelatinases are a type of matrix metalloproteinase (MMP), a family of enzymes that depend on zinc as a cofactor and can break down parts of the extracellular matrix. MMPs have multiple subgroups, including gelatinase A and gelatinase B. Gelatinases are assigned a variety of Enzyme Commission numbers: gelatinase A uses 3.4.24.24, and gelatinase B uses 3.4.24.35, in which the first three numbers are same. The first digit, 3, is the class. Class 3 enzymes are hydrolases, enzymes that catalyze hydrolysis reactions, that is, they cleave bonds in presence of water. The next digit represents sub-class 4, or proteases, which are enzymes who hydrolyze peptide bonds in proteins. The next number is the sub-subclass of 24, which consists of metalloendopeptidases which contain metal ions in their active sites, in this case zinc, which help in cleaving peptide bonds. The last part of the EC number is the serial number, identifying specific enzymes within a sub-subclass. 24 represents gelatinase A, which is a metalloproteinase that breaks down gelatin and collagen, while 35 represents gelatinase B, which hydrolyzes peptide bonds.
Prolyl isomerase is an enzyme found in both prokaryotes and eukaryotes that interconverts the cis and trans isomers of peptide bonds with the amino acid proline. Proline has an unusually conformationally restrained peptide bond due to its cyclic structure with its side chain bonded to its secondary amine nitrogen. Most amino acids have a strong energetic preference for the trans peptide bond conformation due to steric hindrance, but proline's unusual structure stabilizes the cis form so that both isomers are populated under biologically relevant conditions. Proteins with prolyl isomerase activity include cyclophilin, FKBPs, and parvulin, although larger proteins can also contain prolyl isomerase domains.
The complement component 1q is a protein complex involved in the complement system, which is part of the innate immune system. C1q together with C1r and C1s form the C1 complex.
Prolidase deficiency (PD) is an extremely uncommon autosomal recessive disorder associated with collagen metabolism that affects connective tissues and thus a diverse array of organ systems more broadly, though it is extremely inconsistent in its expression.
Thermolysin is a thermostable neutral metalloproteinase enzyme produced by the Gram-positive bacteria Bacillus thermoproteolyticus. It requires one zinc ion for enzyme activity and four calcium ions for structural stability. Thermolysin specifically catalyzes the hydrolysis of peptide bonds containing hydrophobic amino acids. However thermolysin is also widely used for peptide bond formation through the reverse reaction of hydrolysis. Thermolysin is the most stable member of a family of metalloproteinases produced by various Bacillus species. These enzymes are also termed 'neutral' proteinases or thermolysin -like proteinases (TLPs).
Sucrase-isomaltase is a bifunctional glucosidase located on the brush border of the small intestine, encoded by the human gene SI. It is a dual-function enzyme with two GH31 domains, one serving as the isomaltase, the other as a sucrose alpha-glucosidase. It has preferential expression in the apical membranes of enterocytes. The enzyme’s purpose is to digest dietary carbohydrates such as starch, sucrose and isomaltose. By further processing the broken-down products, energy in the form of ATP can be generated.
Carboxypeptidase A usually refers to the pancreatic exopeptidase that hydrolyzes peptide bonds of C-terminal residues with aromatic or aliphatic side-chains. Most scientists in the field now refer to this enzyme as CPA1, and to a related pancreatic carboxypeptidase as CPA2.
Procollagen-proline dioxygenase, commonly known as prolyl hydroxylase, is a member of the class of enzymes known as alpha-ketoglutarate-dependent hydroxylases. These enzymes catalyze the incorporation of oxygen into organic substrates through a mechanism that requires alpha-Ketoglutaric acid, Fe2+, and ascorbate. This particular enzyme catalyzes the formation of (2S, 4R)-4-hydroxyproline, a compound that represents the most prevalent post-translational modification in the human proteome.
The discovery of an orally inactive peptide from snake venom established the important role of angiotensin converting enzyme (ACE) inhibitors in regulating blood pressure. This led to the development of captopril, the first ACE inhibitor. When the adverse effects of captopril became apparent new derivates were designed. Then after the discovery of two active sites of ACE: N-domain and C-domain, the development of domain-specific ACE inhibitors began.
Delta-1-pyrroline-5-carboxylate synthetase (P5CS) is an enzyme that in humans is encoded by the ALDH18A1 gene. This gene is a member of the aldehyde dehydrogenase family and encodes a bifunctional ATP- and NADPH-dependent mitochondrial enzyme with both gamma-glutamyl kinase and gamma-glutamyl phosphate reductase activities. The encoded protein catalyzes the reduction of glutamate to delta1-pyrroline-5-carboxylate, a critical step in the de novo biosynthesis of proline, ornithine and arginine. Mutations in this gene lead to hyperammonemia, hypoornithinemia, hypocitrullinemia, hypoargininemia and hypoprolinemia and may be associated with neurodegeneration, cataracts and connective tissue diseases. Alternatively spliced transcript variants, encoding different isoforms, have been described for this gene. As reported by Bruno Reversade and colleagues, ALDH18A1 deficiency or dominant-negative mutations in P5CS in humans causes a progeroid disease known as De Barsy Syndrome.
Xaa-Pro aminopeptidase is an enzyme. This enzyme catalyses the following chemical reaction
Zingibain, zingipain, or ginger protease is a cysteine protease enzyme found in ginger rhizomes. It catalyses the preferential cleavage of peptides with a proline residue at the P2 position. It has two distinct forms, ginger protease I (GP-I) and ginger protease II (GP-II).
