Product Description

Human C3a desArg is prepared from normal human serum after activation of C3 by human C3 convertase, followed by the removal of the C-terminal arginine by the natural carboxypeptidase N (Hugli, T.E. et al. (1981); Meuller-Ortiz, S.L., et al. (2009)).C3a is a member of the anaphylatoxin family of three proteins (C3a, C4a and C5a) produced by the activation of complement.The desArg form of C3a is an unglycosylated polypeptide containing 76 amino acids with a molecular mass of 8,933 daltons.C3a mediates many inflammatory responses including smooth muscle contraction, vasodilation, increased vascular permeability, and release of histamine from mast cells and basophils (Law, S.K.A. and Reid, K.B.M. (1995)). These activities of C3a are inactivated by removal of the C-terminal arginine and this is complete within minutes after formation in plasma.However, new activities have been identified for C3a desArg acting through the C5L2 receptor (Kalant, D. et al. (2005)).These activities were first assigned to ASP (acylation-stimulating protein), but this was later shown to be identical to C3a desArg.C3a desArg binds to C5L2 with a Kd of approximately 70 nM.In adipocytes, macrophages, fibroblasts and may other cells triglyceride synthesis, glucose transport, and fatty acid uptake are stimulated upon C3a desArg binding in both humans and mice.C3 knockout mice lack ASP function and recombinant C3a desArg is fully functional while C5L2 knockout mice are unresponsive.Many of the biological functions of insulin are expressed by C3a desArg and it also expresses endocrine effects on insulin secretion by pancreatic cells (Maslowska, M. et al (2005)).

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Complement Technology的C1是级联反应中的第一个补体成分，称为补体经典途径。C1与抗原结合的抗体（免疫复合物）结合并被其激活，从而产生引发级联反应的蛋白酶。C1实际上是钙依赖性复合物中结合在一起的三种不同蛋白质（C1q，C1r和C1s）的非共价复合物。C1q通过其六个臂中的两个或多个与IgG或IgM的Fc结构域结合。多臂与免疫复合物的结合被认为会引入压力，从而导致复合物中的两个C1r蛋白（蛋白酶酶原）自身激活，从而产生两种活性的C1r丝氨酸蛋白酶（Morikis，D.和Lambris，JD（2005））。 。这些激活的C1r亚基裂解并激活复合物中的两个C1s蛋白酶酶原。活化的C1裂解补体成分C4，释放出C4a，并启动C4b与活化表面的共价连接。活化的C1也切割C2，并且C2的较大片段结合至表面附着的C4b，形成C4b，C2a，其为经典途径的C3 / C5转化酶。