Acylation stimulating protein

Complement 3 (C3) through its interaction with factors B and D (adipsine) generates C3a. In human body, C3a is rapidily cleaved by carboxypeptidase B or carbxyopeptidase N that remove the carboxyl-terminal arginine to generate C3adesArg. Thus, most of plasmatic C3a is present in C3adesArg form. C3adesArg is more commonly named ASP or acylation-stimulating-protein due to its marked stimulating action on triacylglycerol synthesis in human adipocytes and skin fibroblasts. ASP is also known for its augmentation of glucose transport and inhibiting action on hormone-sensitive lipase. Because of these actions, it is linked to the pathogenesis of obesity. ASP has also been demonstrated to be present at increased levels in patients with obesity, type II diabetes melitus and coronary artery disease.

ASP ligate a specific receptor named C5L2 which is coupled with a G-protein.