Lysine decarboxylase in periodontitis patients

描述（由申请人提供）：在慢性（以前是成人）牙周炎中，细菌破坏牙齿-牙龈交界处，特别是其牙附（DAT）细胞，角化细胞被咀嚼和口腔卫生造成的持续创伤激活。这些快速分裂的细胞形成内基底层的连接上皮（JE），并维持上皮附着。DAT细胞冠状端生长在间隙液上，间隙液穿过乙脑到达牙龈沟底部，靠近感染细菌的部位。我们假设，赖氨酸脱羧酶（LDC），在沟细菌酶，消耗赖氨酸的漏出，饥饿的DAT细胞。少量的LDC会引起一系列事件，导致牙齿附着物的丧失和众所周知的牙周病病原体在牙槽内的定植。口腔卫生控制这种定植，但一些成年人难治性和鉴别增加的碳吞噬菌和其他最不饱和菌生产商。龈沟细菌中LDC的活性可能是决定慢性牙周炎能否通过当前（口腔卫生为基础的）治疗得到控制的关键。本研究的目的是：1)开发新的方法来测量牙龈微生物群（菌斑）中活性ldl的数量；2)用这些方法测定难治性和成功治疗的患者脑沟中的酶活性。最不发达国家的活动将由两种方法确定。第一个试验将在难治性和成功治疗患者的全口牙菌斑提取物中存在饱和量的底物（赖氨酸）时测定酶活性（尸胺合成）。第二个将使用h -a-二氟甲基dl -赖氨酸（DFML），这是一种自杀抑制剂，在LDC的催化中心形成加合物。DFML不是市售的，它将在未标记的情况下合成，并作为本项目的放射性衍生物。放射性标记的加合物的形成应该被过量的未标记的L-DFML或赖氨酸所抑制，而印迹上的放射性量将表明与斑块提取物孵育后活性酶的量。该应用程序预测，在难治性斑块中会有比成功治疗的患者斑块更多的酶活性。这些结果将表明牙龈菌群中ldcs活性与治疗结果的关系，以及ldcs抑制剂如DFML是否可能作为一种新的替代药物治疗预防和控制慢性牙周炎。

DESCRIPTION (provided by applicant): In chronic (formerly adult) periodontitis, bacteria destroy the dento-gingival junction, especially its Dentally attached (DAT) cells, keratinocytes that are activated by persistent trauma from mastication and oral hygiene. These rapidly dividing cells form the internal basement lamina of junctional epithelium (JE) and maintain the epithelial attachment. The DAT cell coronal extremity grows on interstitial fluid that transudes through the JE to the base of a gingival sulcus, near the site of infecting bacteria. We posit that lysine decarboxylase (LDC), a bacterial enzyme in the sulcus, depletes the transudate of lysine, starving the DAT cells. A small amount of LDC causes a cascade of events predisposing to loss of Dental attachment and colonization of the sulci by well-known periodontopathogens. Oral hygiene controls this colonization, but some adults are refractory and discriminated by increased Capnocytophaga spp. and other LDC producers. The activity of LDC from the bacteria in gingival sulci may be critical for determining whether chronic periodontitis can be controlled by current (oral hygiene-based) therapy. The Aims of this study are to: 1) develop new assays for measuring the amount of active LDC in the gingival microbiota (plaque); and 2) use these assays for measuring active enzyme in the sulci from refractory and successfully treated patients. LDC activity will be determined by two methods. The first will determine enzyme activity (cadaverine synthesis) in the presence of a saturating amount of substrate (lysine) in extracts of whole-mouth plaque from refractory and successfully treated patients. The second will use H-a-difluoromethyl DL-lysine (DFML), a suicide inhibitor that forms an adduct at the catalytic center of LDC. DFML is not commercially available and it will be synthesized unlabeled and as a radioactive derivative for this project. Radiolabeled adduct formation should be inhibited by an excess of unlabeled L-DFML or lysine and the amount of radioactivity on blots will indicate the amount of active enzyme after incubation with plaque extracts. The application predicts that there will be more enzyme activity in refractory than in successfully treated patient plaque. The results will indicate the relationship of LDC activity in the gingival sulcular microbiota to therapeutic outcome, and whether LDC inhibitors such as DFML might have utility as a new, alternative pharmacotherapeutic for preventing and controlling chronic periodontitis.