布鲁氏菌侵染抑制剂的合成改造及活性研究

Synthesis modification and activity of Brucella infection inhibitors

目的:研究一种新型抗布鲁氏菌的药物,以求布鲁氏菌病的功能性治愈。方法:通过多肽固相合成法(solid phase peptide synthesis,SPPS)和在液相中进行化学反应等操作,根据布鲁氏菌侵染抑制剂OP11线性肽结构合成改造了三个环肽,即环OP11肽、三氮唑丁肽和三氮唑戊肽。通过二硫苏糖醇(dithiothreitol,DTT)测试了目标多肽的稳定性,并使用绵羊布鲁氏菌测定多肽的抗菌活性。结果:使用绵羊布鲁氏菌测试了目标肽的最低抑菌浓度(minimum inhibitory concentration,MIC),测试结果显示,线性OP11肽、环OP11肽、三氮唑丁肽和三氮唑戊肽的MIC值分别为1.281、0.043、0.059、0.052μg/mL。在DTT存在下,环OP11肽中的二硫键可发生还原反应,其半衰期为8 h,而三氮唑丁肽和三氮唑戊肽对DTT稳定。结论:经改造得到的环OP11肽对绵羊布鲁氏菌抑制作用最强,含三氮唑环的丁肽和戊肽的抗菌活性仅次于含有二硫键的环OP11肽。此外,含有三氮唑环的多肽较含有二硫键的多肽化学性质更为稳定。

Objective:To study a new type of anti-brucella drug,in order to achieve the functional cure of brucellosis.Methods:In this paper,solid phase peptide synthesis(SPPS)and chemical reaction in liquid phase were used to synthesize and modify three cyclic peptides,namely cyclic OP11 peptide,triazole-butyl peptide and triazole-amyl peptide,according to the linear peptide structure of brucella infection inhibitor OP11.The stability of the target peptide was tested by dithiothreitol(DTT)and the antibacterial activity of the peptide was determined by Brucella ovis.Results:Brucella ovis was used to test the minimum inhibitory concentration(MIC)of the target peptide.The results showed that the MIC values of linear OP11 peptide,cyclic OP11 peptide,triazolamide peptide and triazolamide peptide were 1.281,0.043,0.059 and 0.052μg/mL,respectively.In the presence of DTT,the disulfide bond in cyclic OP11 peptide could be reduced with a half-life of 8 h,while triazolbutaditide and triazolamyl peptide were stable to DTT.Conclusion:The modified cyclic OP11 peptide has the strongest inhibitory effect on Brucella melitensis,and the antibacterial activity of triazole-containing butypeptide and pentapeptide is second only to that of disulfide-containing cyclic OP11 peptide.In addition,peptides containing a triazole ring are more chemically stable than peptides containing a disulfide bond.