MeSH definition : The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY.
It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT
C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds
to at least two antibodies (involving C1q), C1r and C1s are sequentially activated,
leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION.;
The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY.
It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT
C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds
to at least two antibodies (involving C1q), C1r and C1s are sequentially activated,
leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION.