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Complement C1s MeSH Descriptor Data 2022


MeSH Heading
Complement C1s
Tree Number(s)
D08.811.277.300.290
D12.776.124.486.274.045.290
D12.776.124.486.274.050.290
Unique ID
D003173
RDF Unique Identifier
http://id.nlm.nih.gov/mesh/D003173
Scope Note
A 77-kDa subcomponent of complement C1, encoded by gene C1S, is a SERINE PROTEASE existing as a proenzyme (homodimer) in the intact complement C1 complex. Upon the binding of COMPLEMENT C1Q to antibodies, the activated COMPLEMENT C1R cleaves C1s into two chains, A (heavy) and B (light, the serine protease), linked by disulfide bonds yielding the active C1s. The activated C1s, in turn, cleaves COMPLEMENT C2 and COMPLEMENT C4 to form C4b2a (CLASSICAL C3 CONVERTASE).
Entry Term(s)
C 1 Esterase
C1 Esterase
C1s Complement
Complement 1 Esterase
Complement 1s
Complement Component 1s
Pharm Action
Immunologic Factors
Registry Number
EC 3.4.21.42
Previous Indexing
Complement 1 (1975-1977)
Esterases (1966-1977)
Public MeSH Note
2006; see COMPLEMENT 1S 1990-2005; for COMPLEMENT 1 ESTERASE see COMPLEMENT ACTIVATING ENZYMES 1978-1989
History Note
2006 (1978)
Date Established
1990/01/01
Date of Entry
1977/05/16
Revision Date
2006/07/05
Complement C1s Preferred
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