Lyophilized. The pentameric cell-binding component that is responsible for binding of the holotoxin to eukaryotic cell surfaces, facilitating entry of the A protomer into receptive cells. Reported to elicit direct cellular responses by binding to several cell surface receptors with oligosaccharide side chains. Also elicits a variety of physiological responses, such as mitogenesis in human T cells, enhancement of aggregation of human platelets, elevation of cytosolic Ca2+ levels, and neutralization of antibody response in mice. Reported to deactivate CCR5 and inhibit the entry of R5 HIV-1 in activated T lymphocytes. Also blocks post-entry step of HIV-1 replication. Purity: Four distinct bands by SDS-PAGE. Contaminants: ≤1% holotoxin by CHO cell assay. Ref.: Alfano, M., et al. 2001. J. Immunol. 166, 1863. Alfano, M., et al. 2000. J. Virol. 74, 8767. Hazes, B., et al. 1996. J. Mol. Biol. 258, 661. Wong, W.S., and Rosoff, P.M. 1996. Can. J. Physiol. Pharmacol. 74, 559. Banga, S., et al. 1987. J. Biol. Chem. 262, 14871. Burns, D.L., et al. 1987. Infect. Immun. 55, 24. Hewlett, E.L., et al. 1983. Infect. Immun. 40, 1198. Sato, Y., et al. 1983. Infect. Immun. 41, 313. Tamura, M., et al. 1982. Biochemistry 21, 5516.
R: 23/24/25; S: 45-36/37/39 |
