The orientation and dynamics of somatostatin in lipid environment

• Main Authors: Yi-Cheng Cheng, 陳亦徵
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/d3k526

碩士 === 朝陽科技大學 === 應用化學系碩士班 === 91 === In this article, NMR methods are applied to explore the orientation and dynamics of somatostatin at lipid surface. The presence of sodium dodecylsulfate (SDS) micelles has been found to cause sequence specific changes in the acid- and base-catalyzed amide proton exchange rates relative to the solution state values. On binding of somatostatin to SDS micelles, the FFWKT segment showed the most obvious decrease in the base-catalyzed amide exchange rates. The sequence-specific effects of micelle association were also observed in the homonuclear nonselective spin-lattice relaxation time (T1). These data combined with paramagnetic broadening observation on peptide protons in the presence of spin-labeled lipids yield a detailed model of the interaction of somatostatin with lipid surface. The association of somatostatin to the SDS micelle is further determined by pulsed-field-gradient NMR technique. The association constant is 1.03×103 M-1. This association is thus proved to be a spontaneous process.