PCSK9-DyLight™ 633

Proprotein convertase subtilisin kexin 9 (PCSK9) is a zymogen and member of the subtilisin serine protease family that reduces protein levels of LDL receptors (LDLRs), the receptor for LDL-cholesterol (LDL-C).{13178,46815} It is primarily expressed in the liver and is composed of an N-terminal prodomain that regulates PCSK9 maturation, a catalytic domain containing a catalytic aspartic acid-histidine-serine triad, and a C-terminal domain that contains the LDLR binding site.{13136,46814,46815} PCSK9 is synthesized as a proprotein that is autocatalytically cleaved to generate the 63 kDa mature protein in which the N-terminal prodomain remains non-covalently bound to the catalytic domain to inhibit further activity.{46814} The mature PCSK9 is secreted and circulates in the plasma where it binds to cell surface-expressed LDLRs, triggering endocytosis and lysosomal degradation of the PCSK9-LDLR complex.{46815} This action decreases LDLR expression and reduces cellular LDL-C uptake. Gain-of-function and loss-of-function PCSK9 mutations have been associated with autosomal dominant hypercholesterolemia and decreased plasma LDL-C levels, respectively, in humans.{46815} Reducing the activity of circulating PCSK9 with monoclonal antibodies or small molecule inhibitors decreases LDL-C levels and reduces the risk of adverse cardiovascular events in individuals with hypercholesterolemia. Cayman's PCSK9-DyLight™ 633 is synthesized as a 75.8 kDa proprotein. After cleavage of the signal peptide (1-30 aa) PCKS9 autocatalytically cleaves to the 13.8 kDa prodomain (aa 31-152) and the 59 kDa mature form (aa 153-692 + 10x His-tag). It can be used for cell-based assays.