Arginine 45 is a major part of the antigenic determinant of human beta 2-microglobulin recognized by mouse monoclonal antibody BBM.1.

摘要: Monoclonal antibody BBM.1 (Brodsky, F.M., Bodmer, W. F., and Parham, P. (1979) Eur. J. Immunol. 9, 536-545) identifies an antigenic determinant of human beta 2-microglobulin (beta 2-M). The binds free HLA-A,B-associated 2-M with similar affinity, showing that the does not involve residues interact HLA-A,B heavy chains. Peptides (SWH.1-5) synthesized from 35-50 sequence specifically inhibit binding to cell surfaces. Their inhibitory activity is destroyed by trypsin treatment. observations (i) bind species other than man, gorilla, chimpanzee (ii) arginine 45 only human-specific residue between positions 35 50 suggested this might be part determinant. This hypothesis was confirmed reversible modification cyclohexanedione. Modification arginines in native single arginine, corresponding position 45, peptide SWH.5 resulted up 95% loss activity. Reversal treatment hydroxylamine complete recovery Rabbit antibodies elicited immunization conjugated bovine serum albumin showed no detectable reaction but did react after sodium dodecyl sulfate-polyacrylamide gel electrophoresis onto nitrocellulose. These results thus identify a region around polypeptide which exposed environment involved chain. Analysis calculating local hydrophilicity indices (Hopp, T. P., Woods, K. R. (1981) Proc. Natl. Acad. Sci. U. S. A. 78, 3824-3828) agree being major Models structure as immunoglobulin domain show loop two layers beta-pleated sheet, also consistent it favors model interacts HLA across four-stranded sheet like constant domain.