C1QB 蛋白, 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 蛋白在 C1（血清补体系统的初始成分）的形成中起着至关重要的作用。C1q 与酶原 C1r 和 C1s 结合，导致 C1 的组装。C1q 的胶原蛋白样区域与 Ca(2+) 依赖性 C1r(2)C1s(2) 酶原复合物相互作用，C1q 的球状头与 IgG 或 IgM 的 Fc 区域接合后，C1 就会被有效激活免疫复合物内的抗体。C1 的活性形式是由 C1q、C1r 和 C1s 以 1:2:2 的摩尔比组成的钙依赖性三分子复合物。C1q 亚组分由九个亚基组成，其中六个是 A 链和 B 链的二硫键连接的二聚体，其余三个形成 C 链的二硫键连接的二聚体。

Human

Sf9 insect cells

C-His

P02746 (Q28-A253)

713  [NCBI]

Approximately 30 kDa

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

无菌粉末.

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.