Siezen R J
Department of Biophysical Chemistry, NIZO, Ede, The Netherlands.
Adv Exp Med Biol. 1996;379:63-73. doi: 10.1007/978-1-4613-0319-0_8.
Homology modelling was used to predict enzyme-substrate interactions in three entirely different subtilisin-like enzymes of unknown three-dimensional structure. i.e. (a) cell-envelope proteinase of Lactococcus lactis, (b) putative leader peptidase for pre-nisin from L. lactis, and (c) human furin. Models were based on known three-dimensional structures of subtilisins and thermitase in complex with inhibitors. Detailed analysis of interactions of the P1-P4 residues of model substrates with the S1-S4 binding sites in each enzyme suggest that electrostatic interactions at all four binding sites can contribute to binding and hence to specificity. In particular, one or more negative charges in the S1 or S4 pockets can lead to a high selectivity for Arg residues in the substrate. Many of the predicted interactions have been confirmed by engineering of either enzyme, substrate or both.
同源建模被用于预测三种三维结构未知的完全不同的类枯草杆菌蛋白酶的酶-底物相互作用。即：(a) 乳酸乳球菌的细胞包膜蛋白酶，(b) 乳酸乳球菌前乳链菌肽的假定前导肽酶，以及 (c) 人弗林蛋白酶。模型基于枯草杆菌蛋白酶和嗜热菌蛋白酶与抑制剂复合物的已知三维结构。对模型底物的P1-P4残基与每种酶中S1-S4结合位点相互作用的详细分析表明，所有四个结合位点的静电相互作用都有助于结合，从而影响特异性。特别是，S1或S4口袋中的一个或多个负电荷可导致对底物中精氨酸残基的高选择性。许多预测的相互作用已通过对酶、底物或两者进行工程改造得到证实。
