Abstract
Human brain serine racemase (hSR) was expressed in large amounts in E. coli with N-terminal His-tag (HishSR). His-hSR expressed in inclusion body was solubilized and purified to homogeneity by Ni-NTA affinity column. Purified His-hSR was refolded in Tween 20/cycloamylose with ∼50% efficiency, and refolded His-hSR was isolated by Q Sepharose column chromatography. The refolding conditions are described in detail. His-hSR catalyzed the elimination of L-Ser as well as L-Ser-O-sulfate to form pyruvate.
Keywords: human brain serine racemase, d-ser, nmda receptor, refolding, detergents, cycloamylose