title: Reaction of peptide 89-169 of bovine myelin basic protein with 2-(2-nitrophenylsulfenyl)-3-methyl-3'-bromoindolenine.
abstract: The C-terminal half of the bovine myelin basic protein, peptide 89-169, was treated with BNPS-skatole [2-(2-nitrophenylsulfenyl)-3-methyl-3'-bromoindolenine], and the products were isolated by repeated gel filtration through Sephadex G-50. They consisted of uncleaved peptide 89-169 in which approximately 30% of the tyrosine had been monobrominated and the tryptophan converted to oxindolealanine, peptide 116-169 modified by partial bromination (30%) of the tyrosine, and two chromatographic forms of peptide 89-115. The major form contained the lactone of dioxindolealanine at the C terminus; the minor form contained the uncyclized oxidation product. Each form of peptide 89-115 was resolved into several components by electrophoresis in polyacrylamide gels (10%, w/w) containing 1 M acetic acid and 8 M urea. The presence of three of these components could be explained by partial deamidation of Asn-91 and Gln-102. Studies on the oxidation of tryptophan-containing model peptides by BNPS-skatole indicated that the reaction can also include partial bromination of the dioxindole and its lactone and partial cleavage at the amino peptide bond of the tryptophan.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001966:Bromine; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004676:Myelin Basic Protein / Q000032:analysis; D010455:Peptides / Q000032:analysis; D012862:Skatole / Q000031:analogs & derivatives; D013056:Spectrophotometry, Ultraviolet; D013434:Sulfenic Acids; D014364:Tryptophan / Q000031:analogs & derivatives
chemical_list: D000596:Amino Acids; D004676:Myelin Basic Protein; D010455:Peptides; D013434:Sulfenic Acids; C005904:BNPS-skatole; D014364:Tryptophan; D012862:Skatole; D001966:Bromine