Hu Fetuin A, 100 _g

STEMCELL Technologies offers Human Recombinant Fetuin A, a plasma glycoprotein belonging to the cystatin superfamily of cysteine protease inhibitors. Also referred to as alpha-2-HS-glycoprotein (AHSG), the protein is expressed with a polyhistidine tag at the C-terminus and is produced in HEK293 cells. It carries alternative names including A2HS, AHS, AHSG, FETUA, and HSGA, corresponding to accession number NP_001613.2 covering residues Ala19–Val367.

In biological systems, Fetuin A forms soluble complexes with calcium and phosphate, supporting clearance of calcium phosphate and helping prevent ectopic calcification. The protein has also been described as participating in lipid transport by acting as a carrier and, in cell-based assays, as protecting against lethal systemic infection by inhibiting high mobility group box 1 (HMGB1) protein accumulation and release. It further acts as a natural antagonist against specific TGF-β and BMP signaling proteins, blocking osteogenic differentiation of rat bone marrow cells.

Lyophilized from sterile PBS at pH 7.2, the product is normally formulated with trehalose (5 - 8%), mannitol, and 0.01% TWEEN® 80 as protectants before lyophilization. It has a predicted molecular mass of 38.8 kDa, with an apparent molecular mass of 55 - 60 kDa due to glycosylation, as resolved by SDS-PAGE under reducing (+) conditions and visualized by Coomassie Blue staining. Purity is ≥ 94%, and the 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 the date of receipt. To prepare, the vial should be centrifuged before opening and reconstituted in sterile water to at least 0.25 mg/mL, without vortexing.