PHOSPHATE ACTIVITY IN BIOLOGICAL FLUIDS

首席研究员最近开发了一种新的离子选择电极 (ISE)，它对磷酸二氢盐的活性做出反应。这种磷酸盐- ISE对磷酸根离子有很好的选择性。 生物上重要的阴离子，如氯化物、乳酸盐和醋酸盐。这个 首席研究员现在建议使用这种磷酸酶-ISE来研究 磷酸盐结合、矿物质饱和度和磷酸盐在 唾液和牙菌斑液体。为了实现这些目标，磷酸盐- ISE将用于以下研究；(1)直接确定 与生物相关的磷酸根离子对的结合常数 明确定义的化学体系中的阳离子。已确定结合常数 通过直接测量磷酸盐的活度将被用于 核实并可能改进已公布的结合常数的准确性； (2)直接测定人唾液中磷酸盐的活性 和牙菌斑液体。磷酸盐物种、钙、镁、钙、镁、钙、钙、镁、钙、镁、钙、钙、镁、钙、镁、镁、钙、镁、 用离子选择电泳法同时测定这些生理样品中的H+和F- 流体将用于计算离子活度积(IAP) 对各种盐类；(3)开发微米级磷酸盐-ISE用于 微量样品中磷酸盐活度的测量。龋齿是一个地点- 斑块数量较少的特定疾病。一个 将开发微米级版本的磷酸盐-ISE以帮助 对这些单点样品的分析；(40测定磷酸盐-ISE 对生理环境很重要的阴离子的选择性系数 实验或生化系统。ISE经常受到干扰 这限制了电极的使用。选择系数 生理缓冲器，如HEPES。帽子等，以及生物阴离子，如 如脂肪酸、有机酸等，将成为成功的必需品 磷酸盐离子选择电泳法或生化分析的应用；(5)研究 磷酸盐离子选择性高于其他离子的机理 离子，结合计算机建模和核磁共振。由此产生的结果是 机理研究可能导致改善磷酸盐-离子交换效率。

The principal investigator recently developed a new ion-selective electrode (ISE) which responds to the activity of dibasic phosphate. This phosphate- ISE has been shown to have good selectivity for phosphate ions over biologically important anions such as chloride, lactate and acetate. The principal investigator now proposes to use this phosphatase-ISE to study phosphate binding, mineral saturation, and the role of phosphatespecies in saliva and dental plaque fluid. To accomplish these goals, the phosphate- ISE will be employed for the following studies; (1) directly determine binding constants for phosphate ion pairs with biologically relevant cations in well-defined chemical systems. Binding constatns determined through the direct measurement of phosphate activities will be used to verify and possibly improve the accuracy of published binding constants; (2) directly determine the activity of phosphate species in human saliva and dental plaque fluid. The activities of phosphate species, Ca2+, Mg2+, H+, and F- determined simultaneously by ISE methods in these physiological fluids will be used to calculate ionic activity products (IAP) with respect to various salts; (3) develop a micron-sized phosphate-ISE for the measurement of phosphate activities in micro-samples. Caries is a site- specific disease where the amount of plaque at that site is small. A micron-sized version of the phosphate-ISE will be developed to assist in the analysis of these single-site samples; (40 determine phosphate-ISE selectivity coefficients for anions that are important for physiological experiments or biochemical systems. ISEs often suffer from interferences that limit the utility of the electrode.Selectivity coefficients for physiological buffers such as HEPES. CAPS, etc., and biological anions such as fatty acids, organic acids, etc., will be essential for the successful application of the phosphate-ISEf or biochemical analysis; and (5) study the mechanism for phosphate-ISE selectivity to phosphate- ions over other ions, in conjunction with computer modeling and NMR. The results from this mechanism study may lead to an improved phosphate-ISE.