Martenson R E, Deibler G E, Kramer A J
Biochemistry. 1977 Jan 25;16(2):216-21. doi: 10.1021/bi00621a009.
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.
牛髓鞘碱性蛋白的C端半段，即89 - 169肽段，用BNPS - 斯咔唑[2 - (2 - 硝基苯磺酰基)-3 - 甲基 - 3'-溴吲哚]处理，产物通过用葡聚糖G - 50反复进行凝胶过滤分离。它们包括未切割的89 - 169肽段，其中约30%的酪氨酸被单溴化，色氨酸转化为氧化吲哚丙氨酸；116 - 169肽段，其酪氨酸部分被溴化(30%)；以及89 - 115肽段的两种色谱形式。主要形式在C端含有二氢吲哚丙氨酸内酯；次要形式含有未环化的氧化产物。在含有1 M乙酸和8 M尿素的聚丙烯酰胺凝胶(10%，w/w)中进行电泳，89 - 115肽段的每种形式都被分离成几个组分。其中三个组分的存在可以用Asn - 91和Gln - 102的部分脱酰胺作用来解释。对含色氨酸的模型肽段被BNPS - 斯咔唑氧化的研究表明，该反应还可能包括二氢吲哚及其内酯的部分溴化以及色氨酸氨基肽键的部分断裂。
