Possible involvement of radical intermediates in the inhibition of cysteine proteases by allenyl esters and amides
作者:Yoshio Takeuchi、Tomoya Fujiwara、Yoshihito Shimone、Hideki Miyataka、Toshio Satoh、Kenneth L. Kirk、Hitoshi Hori
DOI:10.1016/j.bmcl.2008.10.007
日期:2008.12
In order to investigate crystallographically the mechanism of inhibition of cysteine protease by alpha-methyl-gamma,gamma-diphenylallenecarboxylic acid ethyl ester 3, a cysteine protease inhibitor having in vivo stability, we synthesized N-(alpha-methyl-gamma,gamma-diphenylallenecarbonyl)-L-phenylalanine ethyl ester 4. Reaction of 4 with thiophenol, the SH group of which has similar pK(a) value to
为了从晶体学上研究具有体内稳定性的半胱氨酸蛋白酶抑制剂α-甲基-γ,γ-二苯基烯丙基羧酸乙酯3抑制半胱氨酸蛋白酶的机理,我们合成了N-(α-甲基-γ,γ-二苯基烯丙基羰基)-L-苯丙氨酸乙酯4。4与硫酚的反应,其SH基团的pK(a)值与半胱氨酸蛋白酶的pK(a)相似,在环境空气中产生氧介导的自由基加合物6和7,但在低温下未进行无氧条件。在没有氧气的情况下,包括组织蛋白酶B在内的两种硫醇酶的催化活性也降低了。这些结果表明半胱氨酸蛋白酶可以通过氧依赖性自由基机制起作用。