Augmentation of the bactericidal activities of human cathelicidin CAP18/LL-37-derived antimicrobial peptides by amino acid substitutions
Augmentation of the bactericidal activities of human cathelicidin CAP18/LL-37-derived antimicrobial peptides by amino acid substitutions
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DOI：
10.1007/s00011-004-1323-8
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发表时间：
2005-02-01
影响因子：
6.7
通讯作者：
Hirata, M
中科院分区：
文献类型：
--
作者：
Nagaoka, I;Kuwahara-Arai, K;Hirata, M
目的：哺乳动物的髓样细胞和上皮细胞表达多种多肽抗生素(如防御素和防御素)，这些抗生素有助于宿主对入侵微生物的天然防御。其中，人中草药抗菌素CAP18/LL-37(L-1-S-37)对革兰氏阳性菌和革兰氏阴性菌均有较强的抗菌活性。方法：以金黄色葡萄球菌、肺炎链球菌、化脓性链球菌、大肠埃希氏菌和铜绿假单胞菌为靶菌，采用AlamarBlue(TM)比色法测定修饰后的多肽(0.022~4.4um，0.1um~10mug/ml)的抗菌活性。结果：通过用两个L残基取代E-16和K-25，增强了18-聚LKKK的疏水性；进一步用三个K残基取代Q(22)、D-26和N-30，增强了18-聚LKKK的阳离子活性。在多肽衍生物中，18聚体LLKKK对金黄色葡萄球菌(耐甲氧西林和敏感)、肺炎链球菌、化脓性葡萄球菌、大肠杆菌和铜绿假单胞菌表现出最强的抗菌活性，在有效浓度下对大肠杆菌ML-35P具有最强的膜通透性(p<；结论：两亲性人CAP18/LL-37衍生的18-聚多肽的杀菌活性可以通过修饰其疏水性和阳离子来增强，18-聚LKKK是对革兰氏阳性和革兰氏阴性细菌感染具有治疗潜力的多肽中最有效的。
Objective: Mammalian myeloid and epithelial cells express various peptide antibiotics ( such as defensins and cathelicidins) that contribute to the innate host defense against invading micro-organisms. Among these, human cathelicidin CAP18/LL-37 (L-1-S-37) possesses potent antibacterial activities against Gram-positive and Gram-negative bacteria. In this study, to develop peptide derivatives with improved bactericidal actions, we utilized the amphipathic 18-mer peptide (K-15 -V-32) of LL-37 as a template, and evaluated the activities of modified peptides.Methods: Antibacterial activities of the peptides (0.022 similar to 4.4 muM corresponding to 0.1 similar to 10 mug/ml) were assessed by alamarBlue(TM) assay using Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa as target organisms. Furthermore, the membrane-permeabilization activities of the peptides were examined by using E. coli ML-35p as a target.Results: By substituting E-16 and K-25 with two L residues, the hydrophobicity of the peptide (18-mer LL) was increased, and by further substituting Q(22), D-26 and N-30 with three K residues, the cationicity of the peptide (18-mer LLKKK) was enhanced. Among peptide derivatives, 18-mer LLKKK exhibited the most potent antibacterial actions against S. aureus (methicillin-resistant and - sensitive), S. pneumoniae, S. pyogenes, E. coli and P. aeruginosa, and possessed the most powerful membrane-permeabilizing activities against E. coli ML-35p at the effective concentrations ( p < 0.05, 18-mer LLKKK vs. 18-mer LL, 18-mer K-15- V-32 and LL-37).Conclusions: Bactericidal activities of the amphipathic human CAP18/LL-37-derived 18-mer peptide can be augmented by modifying its hydrophobicity and cationicity, and 18-mer LLKKK is the most potent among peptide derivatives with therapeutic potential for Gram-positive and Gram-negative bacterial infections.