Protein reactions with methyl and ethyl vinyl sulfones.
Disulfide bonds of bovine serum albumin and wool were reduced by n-tributylphosphine to sulfhydryl groups that were then modified by methyl or ethyl vinyl sulfone in a nucleophilic addition reaction to S-(beta-ethylsulfonylmethyl)-L-cysteine and S(beta-ethylsulfonylethyl)-L-cysteine, respectively. The reductive alkylation was carried out either simultaneously, with both the reducing and alkylating agents present in the reaction mixture, or sequentially, with the reduced proteins first isolated before alkylation. Amino acid analysis studies showed that authentic, synthetic S-(beta-ethylsulfonylethyl)-L-cysteine eluted as a well-resolved peak after serine but that the peak associated with the corresponding methyl derivative overlapped the corresponding peak due to threonine. The extent of alkylation of the sulfhydryl groups of cysteine, epsilon-NH2 of lysine, and NH groups of the imidazole ring of histidine was also measured by amino acid analysis. The results show that alkyl vinyl sulfones have a strong chemical affinity for protein functional groups.
Masri
M S
MS
Western Regional Research Center, U.S. Department of Agriculture, Albany, California 94710.
Friedman
M
M
D000477:Alkylating Agents; D000478:Alkylation; D000596:Amino Acids / Q000032:analysis / Q000302:isolation & purification; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D003545:Cysteine; D006863:Hydrogen-Ion Concentration; D007633:Keratins; D008956:Models, Chemical; D011506:Proteins / Q000032:analysis; D012710:Serum Albumin, Bovine / Q000032:analysis; D013438:Sulfhydryl Compounds; D013450:Sulfones; D014935:Wool / Q000032:analysis
D000477:Alkylating Agents; D000596:Amino Acids; D011506:Proteins; D013438:Sulfhydryl Compounds; D013450:Sulfones; D012710:Serum Albumin, Bovine; C060916:methyl vinyl sulfone; D007633:Keratins; C060914:ethyl vinyl sulfone; D003545:Cysteine