DETERMINATION OF TIE-LINE FIELDS FOR COEXISTING LIPID PHASES

共存脂质相的联络线场的测定

• 批准号: 8364013
• 负责人: ANDREW SMITH
• 金额: $ 0.37万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8364013
• 关键词: Brain; Cell membrane; Cell model; Cholesterol; Disease; Electron Spin Resonance Spectroscopy; Exhibits; Funding; Grant; Knowledge; Least-Squares Analysis; Lipids; Liquid substance; Methods; Modeling; National Center for Research Resources; Phase; Principal Investigator; Research; Research Infrastructure; Resources; Source; Sphingomyelins; Surface; System; Technology; United States National Institutes of Health; cost; dioleoylphosphatidylcholine; novel

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. A novel method has been developed to determine the tie-lines of any three-component two-phase coexistence region by fitting electron-spin resonance (ESR) spectra obtained from compositions on the coexistence curve and within the coexistence region. The method was applied to the liquid-ordered (Lo) and liquid-disordered (Ld) phase coexistence region of the lipid system brain-sphingomyelin/dioleoylphosphatidylcholine/cholesterol (SPM/DOPC/cholesterol). The essential aspects of the method were a unique parameterization of the coexistence region called a "ruled surface" and knowledge of the coexistence curve. Least-squares fitting of the ESR spectra with the parameterized model resulted in a tie-line field consistent with other known information on this lipid system. The use of the ruled surface allows one to guarantee that tie lines do not cross. The best-fit tie-line field consisted of the set of tie lines which were not exactly parallel; they exhibited a gradual change in slope with the largest slope within the coexistence region connecting the coexistence curve compositions with the highest and lowest cholesterol concentrations. The results were compared with those from more constrained methods of representing the tie-line fields. An accurate determination of the tie-line field of phase coexistence regions in lipid systems is a necessary step in determining coexisting lipid compositions to serve as models of cell plasma membranes.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 已经开发了一种新的方法来通过拟合从共存曲线和共存区域内的组成获得的电子自旋共振（ESR）光谱来确定任何三个组件两相共存区域的系线。 该方法应用于脂质系统脑甲状腺素素/二甲酰磷脂酰胆碱/胆固醇/胆固醇（SPM/DOPC/胆固醇）的液体排序（LO）和液体溶液（LD）相共存在区域。 该方法的基本方面是共存区域的独特参数化，称为“统治表面”和对共存曲线的知识。 ESR光谱与参数化模型的最小二乘拟合导致与该脂质系统上其他已知信息一致的领带场。统治表面的使用使人们可以保证绑线不会交叉。 最合适的领带场由一组不完全平行的领带线组成。他们在坡度上表现出逐渐变化，与共存区域内最大的斜率连接了共存曲线组成，胆固醇浓度最高和最低。 将结果与代表领带场的更受限方法的结果进行了比较。 精确确定脂质系统中相共存区域的平行领域是确定共存脂质组合物以用作细胞质膜模型的必要步骤。