complement
- complement
-
A heat-labile system of enzymes in
plasma associated with response to injury. Activation of the
complement cascade occurs through two convergent pathways. In the classical pathway the formation of antibody/antigen complexes leads to binding of C1, the release of active
esterase that activates
C4 and
C2 that in turn bind to the surface. The C42 complex splits
C3 to produce C3b, an opsonin, and C3a (anaphylatoxin). C423b acts on
C5 to release C5a (anaphylatoxin and
chemotactic factor) leaving C5b that combines with C6789 to form
a cytolytic
membrane attack complex. In the alternate pathway
C3 cleavage occurs without the involvement of C142, and can be activated by IgA, endotoxin, or polysaccharide-rich surfaces (eg.
yeast cell wall, zymosan). Factor B combines with C3b to form
a C3 convertase that is stabilized by Factor P, generating
a positive feedback loop. The alternate pathway is presumably the ancestral one upon which the sophistication of
antibody recognition has been superimposed in the classical pathway. The enzymatic cascade amplifies the response, leads to the
activation and recruitment of leucocytes, increases
phagocytosis and induces killing directly. It is subject to various complex feedback controls that terminate the response.
Dictionary of molecular biology.
2004.
:
Look at other dictionaries:
complément — [ kɔ̃plemɑ̃ ] n. m. • 1308; de l a. fr. complir « remplir »; repris 1690; lat. complementum, de complere « remplir » 1 ♦ Ce qui s ajoute ou doit s ajouter à une chose pour qu elle soit complète. ⇒ achèvement, couronnement. Le complément est… … Encyclopédie Universelle
complement — COMPLEMÉNT, complemente, s.n. 1. Ceea ce se adaugă la ceva spre a l întregi; complinire. 2. Parte secundară a propoziţiei care determină un verb, un adjectiv sau un adverb. 3. Substanţă de natură proteică prezentă în serul normal şi care… … Dicționar Român
Complement — Complément Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom … Wikipédia en Français
Complément à 2 — Complément à deux Le complément à deux est une représentation binaire des entiers relatifs qui permet d effectuer les opérations arithmétiques usuelles naturellement. bit de signe 0 1 1 … Wikipédia en Français
complement — COMPLEMENT. s. m. Ce qui s ajoute à une chose pour lui donner sa perfection. On dit en Théologie, Complément de béatitude, pour exprimer Le comble de la beatitude. La résurrection des corps sera le complément de la béatitude des Saints.Complément … Dictionnaire de l'Académie Française 1798
complement — n Complement, supplement are comparable both as nouns meaning one thing that makes up for a want or deficiency in another thing and as verbs meaning to supply what is needed to make up for such a want or deficiency. Complement implies a… … New Dictionary of Synonyms
Complement — Com ple*ment, n. [L. complementun: cf. F. compl[ e]ment. See {Complete}, v. t., and cf. {Compliment}.] 1. That which fills up or completes; the quantity or number required to fill a thing or make it complete. [1913 Webster] 2. That which is… … The Collaborative International Dictionary of English
complement — complement, compliment, complementary, complimentary 1. Complement and compliment each function as noun and verb; in pronunciation they are largely indistinguishable except that in the verbal function compliment has a fuller i sound in its second … Modern English usage
Complement — (v. lat. Complementum), 1) Ergänzung; 2) (Math.), C. einer Größe ist im Allgemeinen das, was zu dieser addirt werden muß, um ein gewisses Ganze zu erhalten. Complement eines Winkels od. Kreisbogens ist beziehungsweise derjenige Winkel od. Bogen,… … Pierer's Universal-Lexikon
complement — ► NOUN 1) a thing that contributes extra features to something else so as to enhance or improve it. 2) the number or quantity that makes something complete. 3) a word or words used with a verb to complete the meaning of the predicate (e.g. happy… … English terms dictionary
Complement a un — Complément à un Le complément à un est l opération qui inverse la valeur de chacun des bits d un nombre binaire. Il est la première étape du complément à deux. Exemple Ce document provient de « Compl%C3%A9ment %C3%A0 un ». Catégorie :… … Wikipédia en Français
