Human proprotein convertase subtilisin/kexin type 9 (PCSK9), also known as FH3, HCHOLA3, and PC9, GenBank Accession No. NM_174936, a.a. 31-692(end), with C-terminal His- and Avi-tags and a D374T mutation, MW=73.8 kDa, expressed in an HEK293 cell expression system and enzymatically biotinylated using Avitag™ technology. PCSK9 is autocleaved to the ~14 kDa prodomain (a.a. 31-152) and the ~60 kDa mature form (a.a. 153-692), which run at higher MW by SDS-PAGE.