Human C1q Protein

Background:

C1q is part of the C1 complex (C1q, C1r, and C1s) and this complex is the first complement component in the classical pathway of complement. The binding of multiple arms to immune complexes causes the two C1r proteins in the complex (protease zymogens) to auto-activate producing two C1r proteases that cleave and activate the two C1s protease zymogens in the complex. Activated C1s cleaves complement component C4 releasing C4a and initiating covalent attachment of C4b to the activating surface. Activated C1s also cleaves C2 and the larger fragment of C2 binds to the surface-attached C4b forming C4b,C2a which is the C3/C5 convertase of the classical pathway.

Storage:

-70 C or below. Avoid freeze/thaw

Source:

Normal human serum

Activity:

Purity:

> 1,000,000 C1H50 units/mg

>98% by SDS-PAGE

Molecular Weight:

Size:

410,000 Da (18 chains)

1000 µg/vial

Concentration:

1.0 mg/mL

Buffer:

10 mM HEPES, 300 mM NaCl, pH 7.2

Preservative:

None, 0.22 µm filtered