人精液凝固蛋白Ⅰ衍生合成肽在不同pH值及Zn^(2+)浓度下的抗菌活性研究

Investigation on the antibacterial activity of human semenogelin Ⅰ derived-peptides at different pH and concentration of Zn^(2+)

目的研究5种人精液凝固蛋白Ⅰ衍生合成肽在不同PH值及Zn2+浓度下的抗菌活性,探讨人精液凝固蛋白Ⅰ衍生抗菌肽在不同条件下的抗菌机理。方法在前期研究新发现的人精液凝固蛋白Ⅰ衍生肽SgI29及其衍生合成肽(SgI14、SgI19、SgI22及SgI25)具有抗菌活性的基础上,设置不同pH值及不同Zn2+浓度,通过琼脂糖弥散法抗菌试验进一步测定其在此环境下对泌尿生殖道感染常见细菌抗菌活性。结果 SgI29及其衍生合成肽在pH值为4时,无明显抗菌活性,pH值为6和7时,其抗菌活性最强。在试验所设置的不同Zn2+浓度下,各培养皿中均未见细菌生长。结论 pH值是影响人精液凝固蛋白Ⅰ衍生肽抗菌活性的重要因素之一。游离态Zn2+具有较强的抗菌活性,精液中Zn2+的抗菌活性值得进一步研究。

【Objective】 To investigate the antibacterial activity of human Semenogelin Ⅰ Derived-Peptides at different PH and different concentration of Zn2＋.【Methods】 On the basis of functional peptide SgI29 and its four derived-peptides（SgI14,SgI19,SgI22 and SgI25） which showed antibacterial activity in the past experiments,the different pH and different concentration of Zn2＋ was designed in the experiment.In this environment,the antibacterial activity of SgI29 and its derived peptides against Escherichia coli and Pseudomonas aeruginosa was determined with radial diffusion assay.【Results】 SgI29 and its four derived-peptides（SgI14,SgI19,SgI22 and SgI25） had no antibacterial activity against Escherichia coli and Pseudomonas aeruginosa at pH4,but at another pH established in the experiment,SgI29 and its four derived-peptides（SgI14,SgI19,SgI22 and SgI25） had evident antibacterial activity.The bacterium did not grow when cultured at different concentration of Zn2＋.【Conclusions】 The pH was an important factor which influences the antibacterial activity of human Semenogelin Ⅰ Derived-Peptides.Free Zn2＋ has evident antibacterial activities against Escherichia coli and Pseudomonas aeruginosa,and the antibacterial activities of Zn2＋ in semen deserves more research.