Hu Fetuin B, 100 _g

A recombinant human protein expressed in HEK293 cells is available from STEMCELL Technologies as a lyophilized preparation. Fetuin B is a protease inhibitor belonging to the fetuin family of proteins within the cystatin superfamily. Its structure includes two cystatin domains (CY1 and CY2) connected by a linker with a CPDCP-trunk and a C-terminal region (CTR), and it contains a His-residue tag at the carboxyl end of the polypeptide chain.

Fetuin B is a plasma protein originating in the liver and is thought to have functions in female fertility, metabolism, and liver disease. It inhibits the activity of ovastacin, a metalloprotease which causes the hardening of the zona pellucida, and it has been observed to increase apoptosis and inhibit migration and invasion of prostate cancer cells in in vitro and in vivo settings. Elevated serum fetuin B is linked to non-alcoholic fatty liver disease (NAFLD).

The product is lyophilized from sterile PBS at pH 7.4, with trehalose (5–8%), mannitol, and 0.01% TWEEN 80 normally added as protectants before lyophilization. It has a predicted molecular mass of 41.7 kDa and an apparent molecular mass of 55 kDa due to glycosylation. Purity is ≥ 92% and endotoxin level is ≤ 1 EU/μg protein as measured by kinetic Limulus amebocyte lysate (LAL) analysis. The product should be stored at -20 to -80°C and is stable as supplied for 12 months from date of receipt. Alternative names are 16G2, Gugu, and IRL685, and the sequence corresponds to Accession Number NP_055190.2 (Met19-Pro382).