Biomaterial Database

[Alternative complement pathway (author's transl)]. 1979

M Kazatchkine, and U Nydegger, and D T Fearon

The dual role of the alternative complement pathway in recognition of foreign substances by a non-immune host and in the intrinsic regulation of the complement sequence is now well recognized. Activation of this pathway occurs through escape from its regulatory mechanisms induced by the activating principle; its functional expression depends on the respective levels of the component proteins C3, factor B, factor D and properdin, and on the control proteins beta 1H and C3bINA. This article presents recently acquired knowlege on the molecular mechanisms of activation, regulation and behaviour under pathological conditions of the alternative complement pathway.

UI	MeSH Term	Description	Entries
D011414	Properdin	A 53-kDa protein that is a positive regulator of the alternate pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It stabilizes the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) and protects it from rapid inactivation, thus facilitating the cascade of COMPLEMENT ACTIVATION and the formation of MEMBRANE ATTACK COMPLEX. Individuals with mutation in the PFC gene exhibit properdin deficiency and have a high susceptibility to infections.	Complement Factor P,Factor P, Complement
D011415	Complement Factor B	A glycine-rich, heat-labile serum glycoprotein that contains a component of the C3 CONVERTASE ALTERNATE PATHWAY (C3bBb). Bb, a serine protease, is generated when factor B is cleaved by COMPLEMENT FACTOR D into Ba and Bb.	C3 Proactivator,C3PA,Complement 3 Proactivator,Factor B,Properdin Factor B,Bb Fragment of Factor B,Complement Factor B Fragment, Bb,Complement Factor B, Alternative Pathway,Complement Factor B-Derived Fragment Bb,Complement Factor Ba,Complement Factor Bb,Complement Protein B,Complement Protein Factor B,Properdin Factor Ba,Properdin Factor Bb,Properdin Factor Bf,Properdin Factor Bf F1,Bb, Complement Factor,Complement Factor B Derived Fragment Bb,Factor B, Complement,Factor B, Properdin,Factor Ba, Complement,Factor Ba, Properdin,Factor Bb, Complement,Factor Bb, Properdin,Factor Bf, Properdin,Proactivator, C3,Proactivator, Complement 3,Protein B, Complement
D011416	Complement Factor D	A serum protein which is important in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. This enzyme cleaves the COMPLEMENT C3B-bound COMPLEMENT FACTOR B to form C3bBb which is ALTERNATIVE PATHWAY C3 CONVERTASE.	Adipsin,C3 Convertase Activator,C3PA Convertase,Factor D,Properdin Factor D,28 kDa Protein, Adipocyte,C3 Proactivator Convertase,C3PAse,Complement Protein D,D Component of Complement,GBGase,Proactivator Convertase,Activator, C3 Convertase,Complement D Component,Convertase Activator, C3,Convertase, C3 Proactivator,Convertase, C3PA,Convertase, Proactivator,Factor D, Complement,Factor D, Properdin,Protein D, Complement
D003165	Complement System Proteins	Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).	Complement Proteins,Complement,Complement Protein,Hemolytic Complement,Complement, Hemolytic,Protein, Complement,Proteins, Complement,Proteins, Complement System
D003167	Complement Activation	The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.	Activation, Complement,Activations, Complement,Complement Activations
D003170	Complement Pathway, Alternative	Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.	Alternative Complement Pathway,Properdin Pathway,Alternative Complement Activation Pathway,Complement Activation Pathway, Alternative
D003176	Complement C3	A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.	C3 Complement,C3 Precursor,Complement 3,Complement C3 Precursor,Complement Component 3,Precursor-Complement 3,Pro-C3,Pro-Complement 3,C3 Precursor, Complement,C3, Complement,Complement, C3,Component 3, Complement,Precursor Complement 3,Precursor, C3,Precursor, Complement C3,Pro C3,Pro Complement 3
D003180	Complement C3b Inactivator Proteins	Endogenous proteins that inhibit or inactivate COMPLEMENT C3B. They include COMPLEMENT FACTOR H and COMPLEMENT FACTOR I (C3b/C4b inactivator). They cleave or promote the cleavage of C3b into inactive fragments, and thus are important in the down-regulation of COMPLEMENT ACTIVATION and its cytolytic sequence.	C3b Inactivators,C3b Inhibitors,Complement 3b Inactivators,Complement 3b Inhibitors,Complement C3b Inactivators,Complement C3b Inhibitor Proteins,Conglutinogen Activating Factors,Factors, Conglutinogen Activating,Inactivators, C3b,Inactivators, Complement 3b,Inactivators, Complement C3b,Inhibitors, C3b,Inhibitors, Complement 3b
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D050577	Complement C3-C5 Convertases	Serine proteases that cleave COMPLEMENT C3 into COMPLEMENT C3A and COMPLEMENT C3B, or cleave COMPLEMENT C5 into COMPLEMENT C5A and COMPLEMENT C5B. These include the different forms of C3/C5 convertases in the classical and the alternative pathways of COMPLEMENT ACTIVATION. Both cleavages take place at the C-terminal of an ARGININE residue.	C3 Convertase,C 3 Convertase,C3 Activator,C3-C5 Convertase,C5 Cleaving Enzyme,C5 Convertase,Complement 3 Convertase,Complement 5 Convertase,Complement C3 Convertases,Complement C5 Convertases,Activator, C3,C3 C5 Convertase,C3 Convertases, Complement,C3-C5 Convertases, Complement,C5 Convertases, Complement,Complement C3 C5 Convertases,Convertase, C 3,Convertase, C3,Convertase, C3-C5,Convertase, Complement 3,Convertases, Complement C3,Convertases, Complement C3-C5,Convertases, Complement C5