Human inositol hexakisphosphate kinase 2 (IP6K2), also known as IHPK2, InsP6 kinase 2, and PIUS, (GenBank Accession No. NM_016291), a.a. 1-426 (end), with C-terminal His-tag and Avi-tag™, MW=52 kDa, expressed in an E. coli cell expression system and enzymatically biotin-labeled using Avi-tag™ technology.