Michel F, Pons M, Descomps B, Crastes de Paulet A
Eur J Biochem. 1978 Mar;84(1):267-74. doi: 10.1111/j.1432-1033.1978.tb12165.x.
Iodoacetyldiethylstilbestrol was used as an affinity label to alkylate the estrogen binding site of bovine liver glutamate dehydrogenase. This reagent induced inactivation and alkylation of the enzyme. The non-alkylating analogues diethylstilbestrol and estradiol protected the enzyme towards alkylation. The apparent constant of alkylation was of the order of magnitude of I50 for the allosteric inhibition by diethylstilbestrol. These two results suggest that alkylation occurred at the estrogen binding site. The stoichiometry of alkylation was between one and two, depending on the experimental conditions. When the stoichiometry was found to be less than or equal to 1, 90% of the label was bound on cystein residues, 70% of which was carried by cysteine-89, a cysteine residue which is known to be inacessible to iodoacetamide in phosphate buffer in the same conditions of temperature and pH.
碘乙酰己烯雌酚被用作亲和标记物，以烷基化牛肝谷氨酸脱氢酶的雌激素结合位点。该试剂导致酶的失活和烷基化。非烷基化类似物己烯雌酚和雌二醇可保护酶不被烷基化。烷基化的表观常数与己烯雌酚变构抑制的I50数量级相当。这两个结果表明烷基化发生在雌激素结合位点。烷基化的化学计量比在1到2之间，这取决于实验条件。当化学计量比小于或等于1时，90%的标记物结合在半胱氨酸残基上，其中70%由半胱氨酸-89携带，在相同温度和pH条件下的磷酸盐缓冲液中，该半胱氨酸残基已知对碘乙酰胺不可接近。
