| protean | Changeable in form; having the power to change body form, like the amoeba. Origin: G. Proteus, a god having the power to change his form (05 Mar 2000) |
|---|---|
| protease | <enzyme> A proteinase which is any enzyme that catalyses the splitting of interior peptide bonds in a protein. (18 Nov 1997) |
| protease inhibitor | A drug that binds to and blocks HIV protease from working, thus preventing the production of new infectious viral articles. (09 Oct 1997) |
| protease inhibitors | Compounds which inhibit or antagonise biosynthesis or actions of proteases. (12 Dec 1998) |
| protease nexin | <protein> Specific inhibitor of urokinase, thrombin and plasmin. Reported to influence neurite outgrowth by regulating the degree of proteolytic activity and thereby preventing excess degradation of substrate macromolecules and promoting neurite adhesion. (18 Nov 1997) |
| proteases | Enzymes that degrade protein molecules. (14 Nov 1997) |
| proteasome | <cell biology> Proteolytic complexes that degrade cytosolic and nuclear proteins. Implicated in ATP dependent ubiquitin protein complex degradation and in antigen processing in antigen presenting cells. The 20S proteasome (700 kD), essential in ATP ubiquitin degradation pathway, has 13-15 subunits each of which has three or four different peptidase activities. 26S proteasomes may be formed in an ATP dependent fashion from a 20S proteasome and additional components, CF1 (660 kD), CF2 (250 kD) and CF3 (600 kD). Origin: Gr. Soma = body (18 Nov 1997) |
| protection | Synonym: protective block. Origin: see protective (05 Mar 2000) |
| protection test | A test to determine the antimicrobial activity of a serum by inoculating a susceptible animal with a mixture of the serum and the virus or other microbe being tested. Synonym: neutralization test. (05 Mar 2000) |
| protective | <pharmacology> An agent that affords defense against a deleterious influence, such as a substance applied to the skin to avoid the effects of the sun's rays or other noxious influences. Origin: L. Protegere = to cover over (18 Nov 1997) |
| protective agents | Synthetic or natural substances which are given to prevent a disease or disorder or are used in the process of treating a disease or injury due to a poisonous agent. (12 Dec 1998) |
| protective block | An incompletely understood mechanism whereby a pacemaker is protected from being discharged by the impulse from another centre; the mechanism, usually conceived as an encircling zone of unidirectionally refractory tissue permitting egress of impulses from the centre but preventing access to the centre, is seen in operation in ventricular parasystole where the parasystolic centre is protected from discharge by the sinus pacemaker and so is able to maintain its intrinsic rhythm undisturbed. Synonym: entrance block, protection. (05 Mar 2000) |
| protective clothing | Clothing designed to protect the individual against known hazards to which he will be exposed. (12 Dec 1998) |
| protective colloid | A colloid that has the power of preventing the precipitation of suspensoids under the influence of an electrolyte. (05 Mar 2000) |
| protective devices | Devices designed to provide personal protection against injury to individuals exposed to hazards in industry, sports, aviation, or daily activities. (12 Dec 1998) |