Novel therapeutic strategy in the treatment of infectious diseases by anti-microbial, endotoxin-neutralizing proteins.

通过抗微生物、内毒素中和蛋白治疗传染病的新治疗策略。

基本信息

批准号：
10670267
负责人：
HIRATA Michimasa
金额：
$ 2.05万
依托单位：
Iwate Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

We have found 18kDa cationic anti-microbial proteins (CAP18) with LPS-neutralizing activity from rabbit and human neutrophils. The 27mer C-terminal fragment of human CAP 18 (27mer ; CAP18_<109-135>) has been identified as the anti-microbial and LPS-neutralizing domain. We investigated the effects of modification and/or substitution of amino acid residues of CAP18 peptides on their activities. Acetylation of N-terminal and amidation of C-terminal residues of the 27mer in-creased LPS-neutralizing and antimicrobial activities. Substitution of E_<119> and K_<128> of 27mer to L (27LL) or F (27FF) increased LPS binding activity (〜30-40 fold) and also blocked LPS-induced lethality in mice. Substitution of E_<119> to L_<119> increased LPS-binding activity (〜8 -fold), however, this peptide (27L) could not protect vs. endotoxin shock. Truncation of 9 amino acids from the N-terminus of 27mer (18mer : CAP18_<118-135>) resulted in a significant decrease in LPS-binding activity even though both terminuses are chemically modified. Increasing the hydrophobic amino acid residues (Leucin=L) in 18mer (18LL) increased LPS-binding activity (〜30-fold) and anti-microbial activity versus gram-positive bacteria such as MRSA (methicillin resistant staphylococcus aureus ; >3 -folds), however, 18LL could not protect vs. endotoxin shock in mice. Further replacement of three positions of 18LL by lysine (K) significantly increased LPS-binding activity (〜120-fold), antimicrobial activity vs. gram negative bacteria such as E.coli O157 : H7 and S.typhimurium, and protect mice from endotoxin shock.From these results, the importance of the stability of alpha-helical structure, and the balance of hydrophobic/ hydrophilic (basic) amino acid residues in CAP18 peptide was suggested.

我们发现18KDA阳离子抗微生物蛋白（CAP18）具有来自兔和人类中性粒细胞的LPS中和活性。人CAP 18（27mer; CAP18_ <109-135>）的27mer C末端片段已被鉴定为抗微生物和LPS中和域。我们研究了CAP18肽的修饰和/或取代氨基酸残基对其活性的影响。 N末端的乙酰化和27mer抗性LPS中和抗菌活性的C末端残基的肿瘤。将E_ <119>和K_ <128>替换为27mer（27ll）或F（27ff）增加LPS结合活性（〜30-40倍），并且还阻断了小鼠的LPS诱导的致死性。将E_ <119>替换为L_ <119>增加了LPS结合活性（〜8倍），但是，该肽（27L）无法保护与内毒素冲击。从27mer的N端（18mer：CAP18_ <118-135>）截断了9个氨基酸，即使两个末端都经过化学修饰，LPS结合活性也会显着降低。在18mer（18LL）中增加疏水性氨基酸残留物（leucin = L）增加了LPS结合活性（〜30倍）和抗微生物活性与革兰氏阳性细菌，例如MRSA（甲基甲基甲基蛋白抗蛋白抗蛋白抗葡萄球菌葡萄球菌；但是，Aureus;> 3-flolds;> 3-flolds;> 3-flolds;> 3-flolds nly无法保护S. Endoxin indoxin nock nock nock in ofenoxin nock inoxin。赖氨酸（k）进一步替换了三个位置的三个位置，显着增加了LPS结合活性（〜120倍），抗菌活性，抗菌活性与革兰氏阴性细菌，例如e.coli O157：H7和S. typhimurium，并保护小鼠免受内毒素冲击。提出了（基本）CAP18胡椒中的氨基酸残基。