Therapeutic Establishment for Gingival Hyperplasia and Scar Formation by Use of Collagen-Digestible Proteases

使用胶原蛋白消化蛋白酶治疗牙龈增生和疤痕形成的治疗方法的建立

基本信息

批准号：
21592367
负责人：
NEMOTO Takayuki
金额：
$ 3万
依托单位：
Nagasaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2009
资助国家：
日本
起止时间：
2009 至 2011
项目状态：
已结题

项目摘要

Porphyromonas gingivalis and Porphyromonas endodontalis, asaccharolytic black-pigmented anaerobes, are predominant pathogens of human chronic and periapical periodontitis, respectively. They incorporate di-and tri-peptides from the environment as carbon and energy sources. In the present study, we cloned a novel dipeptidyl peptidase(DPP) gene of P. endodontalis ATCC 35406, designated as DPP11. A homology search revealed the presence of a P. gingivalis orthologue, PGN0607, which has been categorized as an isoform of authentic DPP7. DPP11 specifically removed dipeptides from oligopeptides with the penultimate N-terminal Asp and Glu. Arg_<670> is a unique amino acid completely conserved in all DPP11 members, whilst this residue is converted to Gly in all authentic DPP7 members. Substitution analysis suggested that Arg_<670> interacts with an acidic residue of the substrate. Considered to preferentially utilize acidic amino acids, DPP11 ensures efficient degradation of oligopeptide substrates in these gram-negative anaerobic rods.In order to investigate the mechanism of Staphylococcal scalded skin syndrome(SSSS) caused by exfoliative toxin A(ETA), we expressed and purified ETA and its N-terminally truncated(Δ38 andΔ57) and inactive(Ser233Ala) derivatives in E. coli. Recombinant ETA(wt) showed the peptidase activity for LLE-MCA. This is the first report that ETA showed the peptidase activity other than Dsg1. ETA and its dirivatives exerted toxin activity to newborn mice, if ETA derivatives(wt andΔ38) possessed the peptidase activity, while ETAs with no peptidase activity(Δ57 and SerΔ233Ala) did not cause the disease. This finding indicated that the peptidase activity of ETA was indispensible for the toxin activity.

牙龈卟啉单胞菌和牙髓卟啉单胞菌是解糖黑色素厌氧菌，分别是人类慢性牙周炎和根尖周炎的主要病原体，它们将环境中的二肽和三肽作为碳和能源。牙髓牙菌 ATCC 35406 的二肽基肽酶 (DPP) 基因，命名为同源性搜索显示存在牙龈卟啉单胞菌直系同源物 PGN0607，其被归类为真正的 DPP7 的同种型，DPP11 特异性地从具有倒数第二个 N 末端的 Asp 和 Glu 的二肽中去除。在所有 DPP11 成员中完全保守的独特氨基酸，而该残基在所有真正的 DPP7 成员中都转化为甘氨酸。分析表明，Arg_<670>与底物的酸性残基相互作用，考虑到优先利用酸性氨基酸，DPP11确保寡肽底物在这些革兰氏阴性厌氧杆中的降解。为了研究葡萄球菌烫伤皮肤综合征的机制（ SSSS）是由剥脱性毒素A（ETA）引起的，我们表达并纯化了ETA及其N端截短的（Δ38和Δ57)和非活性(Ser233Ala)衍生物在大肠杆菌中表现出对LLE-MCA的肽酶活性这是除Dsg1及其衍生物对LLE-MCA表现出肽酶活性的第一份报告。新生小鼠，如果ETA衍生物（wt和Δ38）具有肽酶活性，而ETA不具有肽酶活性肽酶活性（Δ57和SerΔ233Ala）不会引起该疾病。这一发现表明ETA的肽酶活性对于毒素活性是不可或缺的。