rhPBSF/SDF-1b Lyophilized. Lyophilized from sterile-filtered 30% acetonitrile, 0.1% TFA, 50 µg BSA/µg PBSF/SDF-1b. Recombinant, human PBSF/SDF-1b expressed in E. coli. Supports the proliferation of a stromal cell-dependent pre-B cell line. Found to be a chemoattractant for T lymphocytes and monocytes but not neutrophils. Recently shown to be a ligand for the CXCR4 (fusin/LESTR) receptor that functions as a coreceptor for lymphocyte-tropic HIV-1 strains. Biological activity: ED50 = 50-100 ng/ml as measured by its ability to chemoattract human T lymphocytes cultured in the presence of IL-2. Purity: ≥97% by SDS-PAGE. Contaminants: Endotoxin: ≤100 pg/µg PBSF/SDF-1b. Ref.: Bleul, C., et al. 1996. Nature 382, 829. Oberlin, E., et al. 1996. Nature 382, 833. Nagasawa, T., et al. 1994. Proc. Natl. Acad. Sci. USA 91, 2305. Tashiro, K., et al. 1993. Science 261, 600. |