放线菌代谢物抑制脯酰氨内酞酶活性及培养条件的初步研究

以脯酰氨内酞酶为靶酶,从供试菌中筛选出一株放线菌A45发酵液乙酸乙酯提取物对该酶有较强的抑制活性,并对该活性的部分进行酶抑制动力学实验,结果表明乙酸乙酯提取物对该酶抑制率达到54.2%,且其活性和浓度呈量效关系,其IC50为60.5μg/mL,动力学表现为非竞争抑制类型,抑制常数Ki=119.1μg/mL;以对该酶的抑制率为指标,进行该菌株液体培养条件和培养时间的初步研究,结果最适培养时间为6d,最佳培养基配方（g/L）为可溶性淀粉30 g,酵母浸粉2g,MgSO.47H2O 0.4g,CaCO30.3g,K2HPO40.4g。

Study on prolyl endopeptidase inhibitory activities of the metabolite of actinomyces and its optimization of liquid culture condition

Using prolyl endopeptidase as the target enzyme of screening model in vitro, actinomyces A45 was screened. The assay showed that ethyl acetate extract of actinomyees A45 has strong PEP inhibitory activity. It has dose-dependent manner with IC50 of 60. 5 μg/mL. Further tests revealed that the inhibitory type of the chloroform extracts on PEP was uncompetitive. Inhibitory constant（Ki ） is 119 μg / mL. In order to get higher production of inhibitors, the culture conditions of actinomyces A45 in shake flask were optimized. The result showed that the optimal culture medium （g/L） was 30g soluble starch, 2 g yeast extract powder, 0.4g MgSO4 · 7 H2O, 0.3g CaCO3 , 0.4g K2HPO4, and incubated for 6 days.