C1QB Protein, Human (sf9, His)

C1QB protein plays a vital role in assembling C1, the initial component of the serum complement system. C1q associates with proenzymes C1r and C1s, leading to C1 assembly. The collagen-like regions of C1q interact with the Ca(2+)-dependent C1r(2)C1s(2) proenzyme complex. Efficient C1 activation occurs when the globular heads of C1q engage with Fc regions of IgG or IgM antibodies within immune complexes. Active C1 forms a calcium-dependent trimolecular complex (C1q, C1r, and C1s) in a 1:2:2 molar ratio, with C1q comprising nine subunits—six disulfide-linked dimers of A and B chains and three disulfide-linked dimers of the C chain. C1QB Protein, Human (sf9, His) is the recombinant human-derived C1QB protein, expressed by Sf9 insect cells, with C-His labeled tag. The total length of C1QB Protein, Human (sf9, His) is 226 a.a., with molecular weight of ~30 kDa.

C1QB protein plays a crucial role in the formation of C1, the initial component of the serum complement system. C1q associates with the proenzymes C1r and C1s, resulting in the assembly of C1. The collagen-like regions of C1q interact with the Ca(2+)-dependent C1r(2)C1s(2) proenzyme complex, and efficient activation of C1 occurs upon engagement of the globular heads of C1q with the Fc regions of IgG or IgM antibodies within immune complexes. C1, in its active form, constitutes a calcium-dependent trimolecular complex composed of C1q, C1r, and C1s in a molar ratio of 1:2:2. The C1q subcomponent consists of nine subunits, with six being disulfide-linked dimers of the A and B chains, and the remaining three forming disulfide-linked dimers of the C chain.

Human

Sf9 insect cells

C-His

P02746 (Q28-A253)

713  [NCBI]

Approximately 30 kDa

Greater than 90% as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized from a 0.2 μm filtered solution of 50 mM Tris, 100 mM NaCl, 10% Glycerol, 0.5 mM TCEP, pH 7.5. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Shipping with dry ice.