Rauber P, Wikstrom P, Shaw E
Friedrich Miescher-Institut, Basel, Switzerland.
Anal Biochem. 1988 Feb 1;168(2):259-64. doi: 10.1016/0003-2697(88)90316-8.
The specificity of peptidyl chloromethyl ketones has been used to label proteases in complex biological systems by incorporating tyrosine into the structure for eventual radioiodination. Contrary to results with iodination of proteins, a mild reagent, that is, one which iodinates at neutrality, was unsuitable, giving complex mixtures with poor reproducibility, apparently because of side reactions at the chloromethyl ketone group. On the other hand, iodine monochloride in acetic acid provided clean products. In the cases examined where a tyrosine residue was not appropriate for the specificity of the target protease, this residue was located well displaced from the primary specificity site. The resultant diiodotyrosine-containing derivatives were generally highly active as protease inhibitors. The p-aminobenzoyl group was used as an alternative to tyrosine as an iodinatable component.
肽基氯甲基酮的特异性已被用于在复杂生物系统中标记蛋白酶，方法是将酪氨酸引入结构中以便最终进行放射性碘化。与蛋白质碘化的结果相反，一种温和的试剂，即在中性条件下碘化的试剂并不适用，会产生重现性差的复杂混合物，这显然是由于氯甲基酮基团发生了副反应。另一方面，乙酸中的一氯化碘能提供纯净的产物。在所研究的案例中，如果酪氨酸残基不符合目标蛋白酶的特异性，该残基就会远离主要特异性位点。所得含二碘酪氨酸的衍生物通常作为蛋白酶抑制剂具有高活性。对氨基苯甲酰基被用作酪氨酸的替代物作为可碘化成分。
