A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer

博士 === 國立中正大學 === 化學所 === 98 === Single molecule fluorescence microscopy can reveal individual enzyme actions underlying a broad distribution of enzyme activities in enzymology. The mechanism of gel-state biological model membranes degraded by phospholipase A2 (PLA2) had been suggested to follow a s...

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Main Authors: Chang-Ru Chiu, 邱長儒
Other Authors: Tzyy-Schiuan Yang
Format: Others
Language:en_US
Published: 2009
Online Access:http://ndltd.ncl.edu.tw/handle/46931531800018401534
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spelling ndltd-TW-098CCU050650012015-10-13T18:25:30Z http://ndltd.ncl.edu.tw/handle/46931531800018401534 A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer 運用單一分子螢光的方法來研究眼鏡蛇蛇毒磷脂酵素水解凝膠狀態細胞膜的反應機制 Chang-Ru Chiu 邱長儒 博士 國立中正大學 化學所 98 Single molecule fluorescence microscopy can reveal individual enzyme actions underlying a broad distribution of enzyme activities in enzymology. The mechanism of gel-state biological model membranes degraded by phospholipase A2 (PLA2) had been suggested to follow a scooting mode based on the results of the atomic force microscopy (AFM). However, the direct contact of the AFM tip with membrane surface strongly perturbs the surface properties of lipid membrane. Herein, employment of a method which can directly watch single dye-labeled PLA2 molecules could give new insights to the hydrolysis mechanisms. By tracking the spatial distributions and diffusion motions of single PLA2 molecules on defect contained membranes, we found that PLA2s bound to the boundaries around membrane defects with an initial low-activity period (lag-phase), followed by a burst of PLA2s binding on newly created active sites. Besides, those PLA2 bound after lag-burst period showed immobilized under the ~40 nm spatial resolving power of our detection platform. By direct watching the enzyme motions at single molecule level, a relay model is proposed where the reaction is activated by the initial bound PLA2s which in turn produce composition defects allowing more PLA2s docking to further hydrolyze membrane substrate. Tzyy-Schiuan Yang 楊子萱 2009 學位論文 ; thesis 69 en_US
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language en_US
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description 博士 === 國立中正大學 === 化學所 === 98 === Single molecule fluorescence microscopy can reveal individual enzyme actions underlying a broad distribution of enzyme activities in enzymology. The mechanism of gel-state biological model membranes degraded by phospholipase A2 (PLA2) had been suggested to follow a scooting mode based on the results of the atomic force microscopy (AFM). However, the direct contact of the AFM tip with membrane surface strongly perturbs the surface properties of lipid membrane. Herein, employment of a method which can directly watch single dye-labeled PLA2 molecules could give new insights to the hydrolysis mechanisms. By tracking the spatial distributions and diffusion motions of single PLA2 molecules on defect contained membranes, we found that PLA2s bound to the boundaries around membrane defects with an initial low-activity period (lag-phase), followed by a burst of PLA2s binding on newly created active sites. Besides, those PLA2 bound after lag-burst period showed immobilized under the ~40 nm spatial resolving power of our detection platform. By direct watching the enzyme motions at single molecule level, a relay model is proposed where the reaction is activated by the initial bound PLA2s which in turn produce composition defects allowing more PLA2s docking to further hydrolyze membrane substrate.
author2 Tzyy-Schiuan Yang
author_facet Tzyy-Schiuan Yang
Chang-Ru Chiu
邱長儒
author Chang-Ru Chiu
邱長儒
spellingShingle Chang-Ru Chiu
邱長儒
A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer
author_sort Chang-Ru Chiu
title A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer
title_short A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer
title_full A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer
title_fullStr A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer
title_full_unstemmed A fluorescence single-molecule study of cobra phospholipase A2 action on a supported gel-state lipid bilayer
title_sort fluorescence single-molecule study of cobra phospholipase a2 action on a supported gel-state lipid bilayer
publishDate 2009
url http://ndltd.ncl.edu.tw/handle/46931531800018401534
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