Gamma irradiation-induced damage in proteins and peptides

BIOT 135

Sheng-Xue Xie, sxie@ku.edu1, Todd D. Williams2, Dru Willey3, and Elizabeth M. Topp, topp@ku.edu1. (1) Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Ave., Lawrence, KS 66047, (2) Department of Chemistry, University of Kansas, Lawrence, KS 66045, (3) Clearant, Inc, 11111 Santa Monica Boulevard, Suite 650, Los Angeles, CA 90025
Gamma rays inactivate all known blood-borne viruses, and have been used to sterilize blood products. Gamma irradiation may affect the integrity and function of plasma proteins, however. Gamma irradiation-induced damages were studied using a monoclonal IgG antibody (38C2, Sigma-Aldrich), its heavy chain, bovine serum albumin (BSA), lysozyme or a small peptide (tocinoic acid). Model compounds were irradiated in frozen form. SDS-PAGE demonstrated that aggregates and clipping fragments were generated in proteins after irradiation, and was attributed to the scrambling of disulfide bonds. The inclusion of various free radical scavengers influenced irradiation-induced damage. Antioxidants suppressed aggregate formation of and fragmentation of proteins and the scrambling of disulfide bonds of peptides, enhancing peptide stability.
 

Biophysical and Biomolecular Symposium: Protein Chemical Instability
8:00 AM-11:05 AM, Tuesday, August 21, 2007 BCEC -- 106, Oral

Division of Biochemical Technology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007