蝎毒素抗菌肽CeAP1的生物信息学分析与生物活性鉴定

Functional identification and bioinformatics analysis of antimicrobial peptide CeAP1 from scorpion venom

目的获得蝎毒素抗菌肽基因CeAP1并鉴定其编码多肽生物活性。方法采用生物信息学方法从墨西哥雕像木蝎(Centruroides exilicauda)基因组数据中筛选得到1个新的短链抗菌肽基因CeAP1,其成熟肽序列由17个氨基酸残基组成,二级结构呈现为α-螺旋结构,是一种两亲性α-螺旋型阳离子抗菌肽。采用生物信息学软件分析该基因及其编码多肽的结构等生物学特征,并研究其生物活性。结果抗菌肽CeAP1具有广谱抗菌活性,对金黄色葡萄球菌和巨大芽孢杆菌的最低抑菌浓度(minimal inhibitory concentration,MIC)值分别为16.0μmol/L和32.0μmol/L;尤其是对临床分离的多重耐药革兰阳性菌耐万古霉素肠球菌(vancomycin-resistant Enterococcus,VRE)和耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)均具有较强的抑菌活性,其中对VRE E156和VRE E161菌株的MIC值均为16.0μmol/L;对MRSA 16436和MRSA 16559菌株的MIC值均为32.0μmol/L,并且对人的红细胞有较低的溶血活性。此外,在4×MIC浓度下,CeAP1可在15 min内完全杀死所有培养的MRSA 16436菌株。结论抗菌肽CeAP1对耐万古霉素肠球菌和耐甲氧西林金黄色葡萄球菌具有较强的抗菌活性,可能用于治疗多重耐药菌感染的药物开发,具有潜在的药用价值。

Objective To obtain the cDNA coding for the antimicrobial peptide CeAP1 from scorpion venom and identify its biological activity.Methods In this study,we identified a novel short-chain antimicrobial peptide gene CeAP1 from the bark scorpion Centruroides exilicauda genome by bioinformatics analysis,its mature peptide is composed of 17 amino acid residues,and its secondary structure isα-helix,is a natural cationicα-helical antimicrobial peptide(CαAMP).The structure analyses were conducted by using software and tools online.Then,the peptide were synthesized accordingly and its biological activities will be verified.Results Antimicrobial assay showed that CeAP1 is able to potently inhibit the growth of the tested Staphylococcus aureus and Bacillus megaterium with the minimal inhibitory concentration(MIC)values of 16.0μmol/L and 32.0μmol/L,respectively;especially that CeAP1 has bacteriostatic activity against clinically isolated multiple drug resistance Gram-positive bacteria,such as vancomycin-resistant Enterococcus(VRE)and methicillin-resistant Staphylococcus aureus(MRSA)strains with the MICs 16.0μmol/L and 32.0μmol/L,respectively,and has low hemolysis of human red blood cells.In addition,we found that at a concentration of 4×MIC,CeAP1 completely killed all the cultured MRSA 16436 strain within 15 minutes.Conclusion CeAP1 has the activity against multi-drug resistant(MDR)bacteria and may be used for the treatment of MDR bacteria infection in drug development,which has potential medicinal value.