| protein | <biochemistry> Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen and usually sulphur, the characteristic element being nitrogen and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc. And are involved in oxygen transport, muscle contraction, electron transport and other activities throughout the body and in photosynthesis. Origin: Gr. Protos = first (18 Nov 1997) |
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| protein 4.1 | A peripheral protein that binds tightly to spectrin in the red cell membrane; it also binds to certain glycophorins and helps determine the shape and flexibility of the red blood cell. (05 Mar 2000) |
| SCH9 protein kinase | <enzyme> Acts independently of camp-dependent protein kinase and the transcriptional activator adr1 in controlling yeast adh2 expression Registry number: EC 2.7.1.- (26 Jun 1999) |
| protein A | Protein obtained from Staphylococcus aureus that binds immunoglobulin molecules without interfering with their binding to antigen. Widely used in purification of immunoglobulins and in antigen detection, for example by immunoprecipitation. A very effective B-cell mitogen. (18 Nov 1997) |
| protein A24 lyase | <enzyme> Releases histone 2a and ubiquitin from chromosomal protein a24 Registry number: EC 4.- (26 Jun 1999) |
| protein activator, aminolevulinic acid synthetase | <chemical> From rat liver mitochondria Synonym: aminolevulinic acid synthetase activator (26 Jun 1999) |
| protein acyl kinase | <enzyme> Transfers gamma-phosphate of ATP to a protein acceptor with formation of an acyl phosphate bond Registry number: EC 2.7.2.- (26 Jun 1999) |
| protein acyltransferase | <enzyme> Human placental enzyme active in posttranslational acylation of membrane glycoproteins Registry number: EC 2.3.1.- Synonym: glycoprotein palmitoyltransferase (26 Jun 1999) |
| protein-arginine n-methyltransferase | <enzyme> An enzyme that catalyses the methylation of arginine residues of proteins to yield n-mono- and n,n-dimethylarginine. This enzyme is found in many organs, primarily brain and spleen. Chemical name: S-Adenosyl-L-methionine:protein-L-arginine N-methyltransferase Registry number: EC 2.1.1.23 (12 Dec 1998) |
| protein binding | The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments. (12 Dec 1998) |
| protein-bound iodine | Thyroid hormone in its circulating form, consisting of one or more of the iodothyronines bound to one or more of the serum proteins. (05 Mar 2000) |
| protein-bound iodine test | A formerly used test of thyroid function in which serum protein-bound iodine is measured to provide an estimate of hormone bound to protein in peripheral blood. Synonym: PBI test. (05 Mar 2000) |
| protein-calorie malnutrition | Severe deficiency of protein + inadequate caloric intake = kwashiorkor. (12 Dec 1998) |
| protein-D-aspartate methyltransferase | <enzyme> For protein carboxymethylases consider also protein o-methyltransferase Registry number: EC 2.1.1.77 Synonym: d-aspartyl-l-isoaspartyl methyltransferase, protein d-aspartate-l-isoaspartate methyltransferase, protein l-isoaspartate o-methyltransferase, protein-beta-aspartate methyltransferase, protein-l-isoaspartate methyltransferase, protein l-isoaspartyl methyltransferase, isoaspartyl-aspartyl protein methyltransferase, protein-d-asp methyltransferase, l-isoaspartyl protein carboxymethyltransferase, pcm gene product, pcmt1 gene product (26 Jun 1999) |
| protein deficiency | A nutritional condition produced by a deficiency of proteins in the diet, characterised by adaptive enzyme changes in the liver, increase in amino acid synthetases, and diminution of urea formation, thus conserving nitrogen and reducing its loss in the urine. Growth, immune response, repair, and production of enzymes and hormones are all impaired in severe protein deficiency. Protein deficiency may also arise in the face of adequate protein intake if the protein is of poor quality (i.e., the content of one or more amino acids is inadequate and thus becomes the limiting factor in protein utilization). (12 Dec 1998) |