Nicotinamide phosphoribosyltransferase (NAMPT) (Active) protein
Description
Visfatin is a 55 kDa protein produced and secreted primarily by white adipose tissue. Recently, Visfatin was isolated from visceral fat deposits and shown to possess insulin-mimetic activity. Like insulin, Visfatin exerts hypoglycemic effects by interacting with the insulin receptor. The binding affinity of Visfatin for the insulin receptor is similar to that of insulin, but it does not compete with insulin, suggesting that the two proteins interact with different receptor sites. The circulating levels of Visfatin are much lower than those of insulin and are not affected by feeding, implying that the hypoglycemic effect of Visfatin may not be of physiological importance. Alternative Names: PBEF protein, Pre-B cell colony-enhancing factor protein