Human/Mouse CXCL12/SDF‑1 Biotinylated Antibody

SDF-1 alpha and SDF-1 beta are the first cytokines initially identified using the signal sequence trap cloning strategy from a mouse bone-marrow stromal cell line. These proteins were subsequently also cloned from a human stromal cell line as cytokines that supported the proliferation of a stromal cell-dependent pre-B-cell line. SDF-1 alpha  and SDF-1 beta cDNAs encode precursor proteins of 89 and 93 amino acid residues, respectively. SDF-1 alpha and SDF-1 beta are encoded by a single gene and arise by alternative splicing. The two proteins are identical except for the four amino acid residues that are present in the carboxy-terminus of SDF-1 beta and absent from SDF-1 alpha. The amino acid sequence of SDF-1/PBSF identified the protein to be a member of the chemokine alpha subfamily that lacks the ELR domain. Unlike other known chemokine alpha and beta subfamily members that cluster on chromosomes 4 and 17, respectively, SDF-1/PBSF was mapped to chromosome 10q11.1. SDF-1/PBSF is highly conserved between species, with only one amino acid substitution between the mature human and mouse proteins. SDF-1/PBSF has been found to be a chemoattractant for T-lymphocytes and monocytes, but not neutrophils. SDF-1/PBSF was shown to be a ligand for CXCR4 (fusin/LESTR) receptor that functions as a coreceptor for lymphocyte-tropic HIV-1 strains. SDF-1/PBSF has been found to be a powerful inhibitor of infection by lymphocyte-tropic HIV-1 strains.