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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分别是人类慢性牙周炎和根尖周炎的主要病原菌。它们将来自环境的二肽和三肽作为碳和能源。在本研究中，我们克隆了一个新的二肽基肽酶（DPP）基因，命名为DPP 11。同源性搜索揭示了牙龈卟啉单胞菌直向同源物PGN 0607的存在，其已被归类为真实DPP 7的同种型。DPP 11特异性地从具有倒数第二个N-末端Asp和Glu的寡肽中去除二肽。Arg_<670>是在所有DPP 11成员中完全保守的独特氨基酸，而该残基在所有真正的DPP 7成员中转化为Gly。取代分析表明，精氨酸<670>与底物的酸性残基相互作用。为了研究脱落毒素A（exfoliative toxin A，ETA）引起葡萄球菌烫伤样皮肤综合征（Staphylococcal scalded skin syndrome，SSSS）的机制，我们在大肠杆菌中表达并纯化了ETA及其N端截短（Δ38和Δ57）和失活（Ser 233 Ala）衍生物。杆菌重组ETA（wt）对LLE-MCA显示出肽酶活性。这是首次报道ETA具有Dsg 1以外的肽酶活性。如果ETA衍生物（wt和Δ38）具有肽酶活性，则ETA及其衍生物对新生小鼠具有毒性，而不具有肽酶活性的ETA（Δ57和SerΔ 233 Ala）则不致病。这一发现表明ETA的肽酶活性是毒素活性所必需的。