Stereoisomers of thiol proteinase inhibitor (TPI) were synthesized by a conventional solution method. Among them, iNoc-D-Gln-Val-Ala-Ala-pNA weakly inhibited the aminolytic activity of papain, although iNoc-Gln-Val-Val-Ala-Ala-pNA inhibited papain activity fairly potently. However, the other five D-amino acid-containing peptides did not show any inhibitor effects on papain. The circular dichroism (CD) spectra of the enzyme-peptides mixtures were measured in order to study the relationship between the peptide anilides-papain interaction and the inhibitory activity.
采用传统的溶液法合成了
硫醇蛋白酶抑制剂(
TPI)的立体异构体。其中,iNoc-D-Gln-Val-Val-Ala-Ala-pNA对
木瓜蛋白酶的
氨解活性有较弱的抑制作用,而iNoc-Gln-Val-Val-Ala-Ala-pNA则对
木瓜蛋白酶的活性有相当强的抑制作用。然而,其他五种含 D-
氨基酸的肽对
木瓜蛋白酶没有任何抑制作用。为了研究
苯胺肽-
木瓜蛋白酶相互作用与抑制活性之间的关系,我们测量了酶-肽混合物的圆二色性(CD)光谱。