Knight P
Biochem J. 1979 Apr 1;179(1):191-7. doi: 10.1042/bj1790191.
To understand the extent of the cross-linking of proteins by the bifunctional reagent p-NN'-phenylenebismaleimide, a quantitative study of competing reactions has been undertaken. The two reactive maleimide rings of the bismaleimide are hydrolysed in mildly alkaline aqueous solutions much more rapidly than is the single maleimide ring of the monofunctional analogue N-ethylmaleimide. The kinetics of hydrolysis are second-order, depending on both imide and hydroxyl ion concentration in the pH range 8-10. The hydrolysis of the first imide ring of the bismaleimide is more rapid than the second, with second-order rate constants of 1600 M-1 . s-1 and 500 M-1 . s-1 respectively, at 25 degrees C. The half-times for hydrolysis of the first and second imide rings at pH 9.0 are therefore only 43s and 140s. Because it renders the maleimide ring unreactive towards cysteine, this rapid hydrolysis can limit the extent of cross-linking of proteins by the bismaleimide.
为了了解双功能试剂对苯二异硫氰酸酯使蛋白质交联的程度，已对竞争反应进行了定量研究。双马来酰亚胺的两个反应性马来酰亚胺环在弱碱性水溶液中的水解速度比单功能类似物N - 乙基马来酰亚胺的单个马来酰亚胺环快得多。水解动力学是二级反应，在pH值8 - 10范围内取决于酰亚胺和氢氧根离子的浓度。双马来酰亚胺的第一个酰亚胺环的水解比第二个更快，在25℃时二级速率常数分别为1600 M⁻¹·s⁻¹和500 M⁻¹·s⁻¹。因此，在pH 9.0时，第一个和第二个酰亚胺环水解的半衰期分别仅为43秒和140秒。由于这种快速水解使马来酰亚胺环对半胱氨酸无反应性，所以它会限制双马来酰亚胺使蛋白质交联的程度。
