Structure-Activity Studies and Therapeutic Potential of Host Defense Peptides of Human Thrombin
Structure-Activity Studies and Therapeutic Potential of Host Defense Peptides of Human Thrombin
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DOI：
10.1128/aac.01515-10
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发表时间：
2011-06-01
影响因子：
4.9
通讯作者：
Schmidtchen, Artur
中科院分区：
文献类型：
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作者：
Kasetty, Gopinath;Papareddy, Praveen;Schmidtchen, Artur
人凝血酶c端区域的肽在蛋白水解后被释放，并在人体伤口中被鉴定。在这项研究中，我们想调查最小的决定因素，以及结构特征，控制抗菌和免疫调节活性的肽区域。研究人员对GKYGFYTHVFRLKKWIQKVIDQFGE （GKY25）进行了序列氨基酸缺失，并在战略和结构相关的位置进行了替换，随后对革兰氏阴性菌大肠杆菌和铜绿假单胞菌、革兰氏阳性菌金黄色葡萄球菌和白色念珠菌进行了抗菌活性分析。此外，我们还研究了肽对脂多糖（LPS）、脂壁酸或酶生蛋白诱导的巨噬细胞活化的影响。凝血酶衍生的肽显示出长度和序列依赖的抗菌和免疫调节作用。在巨噬细胞模型中，肽长度至少需要20个氨基酸才能达到有效的抗炎作用，并且通过MIC试验判断其具有最佳的抗菌活性。然而，较短的（bbbb12个氨基酸）变异也显示出显著的抗菌作用。中心K14残基对最佳抗菌活性很重要。最后，一种肽变体GKYGFYTHVFRLKKWIQKVI （GKY20）表现出更高的选择性，即低毒性，并保留了抗菌和抗炎作用，在LPS休克和铜绿假单胞菌脓毒症小鼠模型中显示出有效性。这项工作定义了凝血酶c端宿主防御肽的结构-活性关系，并描述了选择治疗感兴趣的肽表位的策略。
Peptides of the C-terminal region of human thrombin are released upon proteolysis and identified in human wounds. In this study, we wanted to investigate minimal determinants, as well as structural features, governing the antimicrobial and immunomodulating activity of this peptide region. Sequential amino acid deletions of the peptide GKYGFYTHVFRLKKWIQKVIDQFGE (GKY25), as well as substitutions at strategic and structurally relevant positions, were followed by analyses of antimicrobial activity against the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, the Gram-positive bacterium Staphylococcus aureus, and the fungus Candida albicans. Furthermore, peptide effects on lipopolysaccharide (LPS)-, lipoteichoic acid-, or zymosan-induced macrophage activation were studied. The thrombin-derived peptides displayed length-and sequence-dependent antimicrobial as well as immunomodulating effects. A peptide length of at least 20 amino acids was required for effective anti-inflammatory effects in macrophage models, as well as optimal antimicrobial activity as judged by MIC assays. However, shorter (> 12 amino acids) variants also displayed significant antimicrobial effects. A central K14 residue was important for optimal antimicrobial activity. Finally, one peptide variant, GKYGFYTHVFRLKKWIQKVI (GKY20) exhibiting improved selectivity, i.e., low toxicity and a preserved antimicrobial as well as anti-inflammatory effect, showed efficiency in mouse models of LPS shock and P. aeruginosa sepsis. The work defines structure-activity relationships of C-terminal host defense peptides of thrombin and delineates a strategy for selecting peptide epitopes of therapeutic interest.