牙龈卟啉单胞菌血凝素2与氯化血红素结合位点分析

项目名称： 牙龈卟啉单胞菌血凝素2与氯化血红素结合位点分析

项目编号： No.81470753

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 杨秋波

作者单位： 首都医科大学

项目金额： 67万元

中文摘要： P.g的血凝素2（HA2）与氯化血红素（hemin）的卟啉环结合，为P.g提供营养增强P.g毒性。我们前期研究明确了HA2与hemin结合位点是HA2的1001号组氨酸。本研究提出假说，以1001号组氨酸为靶点的方法可能在抑制P.g摄取hemin，控制P.g生长方面起作用。本课题旨在进一步明确这个结合位点并研究以此位点为靶点的控制P.g生长方法。研究内容，1采用X- 射线晶体衍射分析方法，蛋白质核磁共振( NMR)技术，蛋白质结构预测，分析HA2与hemin复合物的结构以确认这个结合位点。2 包含HA2的1001号组氨酸的多肽片段的抑制HA2与hemin结合，控制P.g生长的作用。3 以包含HA2的1001号组氨酸的多肽片段为抗原的主动免疫对P.g在大鼠引起的牙周炎的预防作用。4 抗P.g包含HA2的1001号组氨酸的多肽片段的单克隆抗体的制备，及单抗对HA2与hemin结合的抑制作用。

中文关键词： 牙龈卟啉单胞菌；血凝素；结合位点

英文摘要： The HA2 domain binds to hemoglobin specifically through the porphyrin ring of heme moiety for the acquisition of iron and porphyrin. In our previous study, the key residues involved in HA2 hemin-binding activity was identified. Residue H1001 of HA2 is involved in the hemin-binding mechanism of P. gingivalis rHA2. Based on these results, we propose the hypothesis that residue H1001 may be an target in inhibition of P. gingivalis rHA2 hemin binding and its growth. The overall goal of the study is to determine whether residue H1001 is an target in inhibition of P. gingivalis rHA2 hemin binding and its growth or not. Specific Aim 1: confirm the protein structure and hemin binding site. Crystals obtained from the protein by hanging-drop vapor-diffusion method will be examined by means of X-ray crystallography, Nuclear Magnetic Resonance technique and protein structure prediction. Specific Aim 2: Determine the effect of peptide containing the hemin binding residue (H1001) of HA2 on inhibition of the hemin uptake and growth of P. gingivalis . Specific Aim 3: Determine the effectiveness of immunization with peptide containing the hemin binding residue (H1001) of HA2 on protection against experimental periodontal bone loss following infection with P. gingivalis. Specific Aim 4: Determine the effect of monoclonal antibody against peptide containing the hemin binding residue (H1001) of HA2 on inhibition of the hemin uptake and growth of P. gingivalis .

英文关键词： Porphyromonas gingivalis;hemagglutinin;binding site