Human Hypoxanthine-guanine phosphoribosyltransferase (HGPRT, EC 2.4.2.8)

NOVOCIB's human HGPRT enzyme is a 25kDa purified protein cloned by RT-PCR amplification of mRNA extracted from human hepatoma cells and expressed in E.coli. The sequence of cloned HGPRT (accession number P00492) was confirmed by DNA sequencing (100% identity).

NOVOCIB's cloned human HGPRT is a highly active enzyme that catalyzes the reversible transfer of the 5-phosphoribosyl group between α-D-5-phosphoribosyl-1-pyrophosphate (PRPP) and a purine base (hypoxanthine or guanine) to form a purine nucleotide IMP or GMP. The enzyme has been characterized for its affinity for natural substrates and velocity in forward and reverse directions.

Supplied in stable form (lyophilized), this enzyme provides an excellent positive control for in vitro HGPRT assay protocols when testing protein expression and activity in cell lysates.

	Storage: HPRT enzyme is provided in lyophilized form and should be stored at –20°C. Unit Definition: (forward reaction) One unit of hypoxanthine-guanine phosphoribosyl transferase converts 1 µmole of hypoxanthine to IMP per minute at pH 8.8 at 25°C, as measured by a coupled IMPDH enzyme system. (see HPRT Assay Kit for further details) Specific Activity: ≥ 1 Unit/mg protein. Purity: controlled by 12%AA SDS-PAGE.

References G.K. Balendiran et al. (1999): Ternary complex structure of human HGPRTase, PRPP, Mg2+, and the inhibitor HPP reveals the involvement of the flexible loop in substrate binding Protein Sci. 8(5), 1023-1031