| protein hybridization | The formation of a protein consisting of two or more polypeptide chains from separate and different polypeptide chains. (12 Dec 1998) |
|---|---|
| protein hydrolysate | A sterile solution of amino acids and soft chain peptides prepared from a suitable protein by acid or enzymatic hydrolysis; used intravenously for the maintenance of positive nitrogen balance in severe illness, and after surgery involving the alimentary tract; or used orally in the diets of infants allergic to milk or as a supplement when high protein intake from ordinary foods cannot be accomplished. (05 Mar 2000) |
| protein isoprenylation | A post-translational modification of proteins by the attachment of an isoprenoid to the c-terminal cysteine residue. The isoprenoids used, farnesyl diphosphate or geranylgeranyl diphosphate, are derived from the same biochemical pathway that produces cholesterol. (12 Dec 1998) |
| protein kinase | <enzyme> Enzyme catalysing transfer of phosphate from ATP to hydroxyl side chains on proteins, causing changes in function. most phosphate on proteins of animal cells is on serine residues, less on threonine, with a very small amount on tyrosine residues. Tyrosine kinases phosphorylate proteins on tyrosine, serine / threonine kinases on serine or threonine. (18 Nov 1997) |
| protein kinase B kinase | <enzyme> Phosphorylates and activates protein kinase b on threonine-308; requires phosphatidylinositol-3,4,5-trisphosphate Registry number: EC 2.7.10.- Synonym: upstream kinase, pkb kinase (26 Jun 1999) |
| protein kinase c | <enzyme> An enzyme that phosphorylates proteins on serine or threonine residues in the presence of physiological concentrations of calcium and membrane phospholipids. The additional presence of diacylglycerols markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by phorbol esters and it is believed that protein kinase c is the receptor protein of tumour-promoting phorbol esters. Registry number: EC 2.7.1.- (12 Dec 1998) |
| protein kinases | <enzyme> A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein. Chemical name: ATP-protein phosphotransferase Registry number: EC 2.7.1.37 (12 Dec 1998) |
| protein-losing enteropathies | A series of gastrointestinal disorders which share in common the excessive loss of protein, mainly albumin, across the gut wall. They occur in the stomach (menetrier disease), as well as the small bowel (intestinal lymphangiectases, assorted inflammatory states). They are also occasionally associated with congestive heart failure (again a small bowel protein loss). (12 Dec 1998) |
| protein-losing enteropathy | Condition in which plasma protein is lost to excess into the intestine. This can be due to diverse causes including gluten enteropathy, extensive ulceration of the intestine, intestinal lymphatic blockage, and infiltration of leukaemic cells into the intestinal wall. (12 Dec 1998) |
| protein-lysine 6-oxidase | <enzyme> An enzyme oxidizing peptidyl-lysyl-peptide in the presence of water & molecular oxygen to yield peptidyl-allysyl-peptide plus ammonia & hydrogen peroxide. Chemical name: Protein-L-lysine:oxygen 6-oxidoreductase (deaminating) Registry number: EC 1.4.3.13 (12 Dec 1998) |
| protein malnutrition | Children are particularly prone to develop protein malnutrition. To grow, children have to consume enough nitrogen-containing food (protein) to maintain a positive nitrogen balance whereas adults need only be in nitrogen equilibrium. (12 Dec 1998) |
| protein metabolism | Decomposition and synthesis of protein in the tissues. Synonym: proteometabolism. (05 Mar 2000) |
| protein methylesterase | <enzyme> Hydrolyzes protein methyl esters to yield methanol and unmethylated protein; found in bacterial and human cells Registry number: EC 3.1.1.- (26 Jun 1999) |
| protein methyltransferases | <enzyme> Enzymes that catalyze the methylation of amino acids after their incorporation into a polypeptide chain. S-adenosyl-l-methionine acts as the methylating agent. Registry number: EC 2.1.1 (12 Dec 1998) |
| protein NH2-terminal asparagine deamidase | <enzyme> Converts amino terminal asparagine to aspartic acid; from porcine liver; mw about 33 kD Registry number: EC 3.5.1.- Synonym: porcine pnad (26 Jun 1999) |