The structural reorganization of vesicle membranes that occur due to a pH dependent complexation of the membranes with poly(2-ethylacrylic acid) (PEAA) was investigated. The kinetics of the reorganization were examined by monitoring the changes in the turbidity of vesicle suspensions that occurs during the reorganization. The response of the rate of reorganization to pH, temperature, and membrane composition was studied. It was found that the reorganization behaved similarly to the solubilization of phosphatidylcholine vesicle by apolipoproteins. Permeability changes accompanying the process were recorded by monitoring the fluorescence changes of vesicle suspensions containing a fluorescent marker. The rate of change in permeability was found to be fast relative to the rate of structural reorganization. PEAA was labeled with the dansyl chromophore. Fluorescence microscopy was used to visualize the interaction of the labeled polymer (DnsPEAA) with egg yolk phosphatidylcholine vesicles. Adsorption of DnsPEAA onto vesicle surfaces produced a concentration of fluorescence on the vesicles. Following acidification of these samples, vesicles reorganized into many smaller particles with a diffusion of fluorescence. The reorganization was sensitized to the presence of glucose by incorporating the enzyme, glucose oxidase, into vesicles suspensions containing PEAA. The rate of permeability increase of membranes could be controlled by adjusting the concentrations glucose, enzyme, oxygen and PEAA.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-7896 |
| Date | 01 January 1990 |
| Creators | Devlin, Brian Patrick |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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