CD157, also known as bone marrow stromal cell antigen 1 (BST-1), is a glycosyl phosphatidylinositol anchored membrane protein that belongs to the CD38 family (1). CD157 was discovered in a bone marrow stromal cell line where it facilitates pre-B-cell growth (2, 3). Along with CD38, CD157 is a bifunctional ectoenzyme that exhibits both ADP-ribosyl cyclase and cyclic ADP ribose hydrolase activities (2). It may play a role in rheumatoid arthritis (RA) due to its enhanced expression in RA-derived bone marrow stromal cell lines (3). CD157 has been predicted to function as a cell surface receptor and an immunoregulatory molecule (4). Source: Recombinant human CD157 encoded by the BST-1 gene (rhCD157, aa29 to 292, GARARWRGEGT. Accession Q10588) was expressed with a C-terminal 6X His tag in a murine myeloma cell line, NS0. Definition: Measured by its ability to cyclize nicotinamide guanine dinucleotide (NGD+). Specific Activity: 20pmol/min/ug. Applications: Suitable for use in Western Blot. Other applications not tested. Recommended Dilution: Western Blot: Predicted 31kD and migrates as a doublet at 38 and 40kD bands in SDS-PAGE under reducing conditions. Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4C for short-term only. For long-term storage, store at -20C. Aliquots are stable for at least 6 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
