BACTERICIDAL ACTIVITY OF LACTOFERRIN ON ORAL FLORA

乳铁蛋白对口腔菌群的杀菌活性

• 批准号: 3220327
• 负责人: ROLAND R ARNOLD
• 金额: $ 26.46万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-08-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3220327
• 关键词: Streptococcus mutans; anaerobic bacteria; antibacterial agents; antibacterial antibody; cell membrane; cell wall; chemical binding; chemical structure function; electron microscopy; enzyme linked immunosorbent assay; enzyme mechanism; glycoproteins; granulocyte; human milk; human tissue; immunofluorescence technique; immunoglobulin A; laboratory mouse; laboratory rabbit; lactoferrin; lysozyme; membrane activity; metal complex; methylation; microorganism culture; monoclonal antibody; neutrophil; oral bacteria; oxidation reduction reaction; peptidases; periodontium disorder; phagocytosis; physical chemical interaction; protease inhibitor; proteolysis; radiotracer; saliva; secretory immune system

Lactoferrin (LF), a principal glycoprotein component of secretions that bathe mucosal surfaces and of the specific granules of neutrophils (PMN), is capable of high affinity coordinate binding of Fe3+ and CO3 2- It has been shown to have bacteriostatic proper- ties related to its ability to with-hold iron and is capable of a potent bactericidal effect that is independent of this iron deprivation. The overall objectives of these continuing studies are to characterize the mechanisms of LF killing and determine the nature and biological significance of IgA-LF interactions. Specifically, the distribution and quantity of IgA-LF complex in human milk and saliva will be determined using ELISA procedures specific for this complex. IgA-LF complex will be isolated and characterized as to the physicochemical nature of the association, its antibody specificity, and its bactericidal activity as it relates to antibody specificity. An in vitro model for IgA-LF complexity will be examined using various IgA preparations. The kinetics and nature of this association will be examined using methods similar to that used for determining SC binding to IgA. Determination of the active sites of the LF molecule responsible for bactericidal activity will be pursued using proteolytic and chemical digestion and isolation of the defined fragments. Their biological activity and the nature of their binding to target sites will be examined. The possibility that proteolytic cleavage of Lf may be important in the sequence of events leading to expression of cidal activity will be approached using various protease inhibitors in the cidal reaction mixtures. LF target sites on the surface of bacteria will be examined using LF that has been labeled using mild reductive methylation. The influence of surface modification of bacteria on kinetics of binding of LF will be examined and the relationship of binding kinetics to bactericidal activity will be determined. The possible involvement of radical mechanisms in LF-mediated toxicity will be investigated by determining the nature of damage to target microorganisms determining the effects of anaerobiosis and various radical scavengers in LF cidal activity and by comparing LF effects with those of known radical generators. LF will be purified from both PMN and saliva and the biochemistry and biological activity compared with that of milk LF. The role of LF in the bacteria dal activity of the PMN will be examined using LF depletion/reconstitution studies with neutrophils and a dual staining procedure for the simultaneous determination of phagocytosis and killing of target microorganisms.

乳铁蛋白（LF），分泌物的主要糖蛋白成分 那个浴粘膜表面和特定的颗粒 中性粒细胞（PMN）能够具有高亲和力坐标结合 fe3+和co3 2-已显示其具有抑菌性 与其具有持有铁的能力相关的关系，并且能够 与该铁无关的有效杀菌作用 剥夺。 这些继续研究的总体目标 要表征LF杀戮的机制并确定 IgA-LF相互作用的性质和生物学意义。 具体而言，IgA-LF复合物的分布和数量 人牛奶和唾液将使用ELISA程序确定 对于这个复合物而言。 Iga-LF复合物将被隔离，并且 关于关联的理化性质的特征 它的抗体特异性及其杀菌活性 与抗体特异性有关。 IgA-LF的体外模型 将使用各种IGA制剂检查复杂性。 这 该关联的动力学和性质将使用 类似于用于确定SC与IgA结合的方法。 LF分子负责的活性位点的测定 对于杀菌活性，将使用蛋白水解和 定义片段的化学消化和隔离。 他们的 生物活性及其与目标位点结合的性质 将被检查。 LF的蛋白水解裂解的可能性 在事件序列中可能很重要，导致表达 将使用各种蛋白酶进行CIDAL活动 CIDAL反应混合物中的抑制剂。 LF目标站点 将使用已标记的LF检查细菌表面 使用轻度还原性甲基化。 表面的影响 细菌在LF结合动力学上的修饰将是 检查和结合动力学与杀菌的关系 将确定活动。 激进的可能参与 LF介导的毒性机制将通过 确定目标微生物损害的性质 确定厌食症和各种自由基的影响 清除LF CIDAL活动的清除剂，并通过将LF效应与 已知激进发电机的那些。 LF将从两者中纯化 PMN和唾液以及生物化学和生物活性 与牛奶LF相比。 LF在细菌DAL中的作用 PMN的活动将使用LF检查 用中性粒细胞和双重研究的耗竭/重建研究 同时确定的染色程序 吞噬作用和靶标微生物的杀死。