| retinol-binding protein | <molecular biology> Proteins which bind with retinol. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of 21,000-22,000. The protein has one binding site for retinol and is responsible for the transport of vitamin A. The retinol- protein complex (molecular weight 80,000 to 90,000) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14,000 and carries retinol as a non-covalently-bound ligand. (03 Jul 1999) |
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| periplasmic binding proteins | Transport proteins located within the periplasmic space. Some act as receptors for bacterial chemotaxis, interacting with MCPs. Their mode of action is unclear. (18 Nov 1997) |
| ribose binding protein | <protein> Periplasmic binding proteins of bacteria that interact either with the ribose transport system or with the methyl accepting chemotaxis protein MCP III (trg). (18 Nov 1997) |
| ribosome binding site | The region of a messenger RNA molecule that binds the ribosome to initiate translation. (09 Oct 1997) |
| GTP-binding protein | <molecular biology, protein> There are two main classes of G-proteins, the heterotrimeric G proteins that associate with receptors of the seven transmembrane domain superfamily and are involved in signal transduction and the small cytoplasmic G-proteins. Regulatory proteins found in all cells. They are versatile molecular switches, involved in the control of a wide range of biological processes - protein synthesis, signal transduction pathways, growth and differentiation. They all act through a common molecular mechanism based on their ability to bind the guanine nucleotides GTP and GDP selectively and with high affinity. Stimulatory G-proteins are permanently activated by cholera toxin, inhibitory ones by pertussis toxin. Transducin was one of the first of the heterotrimeric G-proteins to be identified. The small G-proteins are a diverse group of monomeric GTPases that include ras, rab, rac and rho and that play an important part in regulating many intracellular processes including cytoskeletal organisation and secretion. Their GTPase activity is regulated by activators (GAPs) and inhibitors (GIPs) that determine the duration of the active state. (12 Jul 2000) |
| RNA-binding proteins | Proteins which bind to RNA molecules. Certain structure motifs are common to several of the proteins, such as arginine (arg)-rich tracts, typically consisting of alternating arg-asp, arg-ser, or arg-gly residues. These proteins also tend to have a common ribonucleotide sequence domain. (12 Dec 1998) |
| guanosine triphosphate binding protein | <protein> A type of protein embedded in the cytoplasmic membrane of the cell which transmits signals from outside the cell (such as from hormones binding to receptors on the outside of the cell) to the inside of the cell, where it causes some sort of biochemical reaction within the cell to the signal (such as the altering of metabolic pathways or gene expression). The process by which the protein does this is unclear but involves exchanging a molecule of GDP for a molecule of GTP. (09 Oct 1997) |
| placental calcium-binding protein | <protein> Calcium binding protein of placenta, uterus and vasculature containing the EF hand motif. (18 Nov 1997) |
| competitive binding assay | General term for an assay in which a binder competes for labelled versus unlabelled ligand; following separation of free and bound ligand, the ligand (the analyte assayed) is quantitated by relating bound and unbound ratios to known standards. See: enzyme-linked immunosorbent assay, radioreceptor assay, immunoassay, enzyme-multiplied immunoassay technique, radioimmunoassay. Synonym: displacement analysis, saturation analysis. (05 Mar 2000) |
| complement binding assay | A test for the detection of immune complexes. (05 Mar 2000) |
| Con A binding site | <biochemistry> A common misuse of the term receptor. Con A binds to the mannose residues of many different glycoproteins and glycolipids and the binding is therefore not to a specific site. It could be argued that the receptor is the Con A and cells have Con A ligands on their surfaces: certainly this would be less confusing. (05 Jan 1998) |
| corticosteroid-binding protein | <chemical> Chemical name: Transcortins (12 Dec 1998) |
| heparin binding growth factor | <growth factor> Acidic fibroblast growth factor (alpha FGF, HBGF 1) and basic FGF (beta FGF, HBGF 2) are the two founder members of a family of structurally related growth factors for mesodermal or neuroectodermal cells. Synonym: heparin binding growth factor. Acronym: FGF (18 Nov 1997) |
| 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) |
| serotonin-binding protein kinase | <enzyme> An aspect of protein kinases EC 2.7.1.37 Registry number: EC 2.7.1.- Synonym: sbp kinase (26 Jun 1999) |