Publication Date
1-1-1992
Document Type
Dissertation/Thesis
First Advisor
Gasser, Kenneth W.
Degree Name
B.S. (Bachelor of Science)
Legacy Department
Department of Biological Sciences
Abstract
Rat pancreatic zymogen granules were studied to assess their role in exocytotic fusion. The granules were isolated by nitrogen cavitation and Percoll density gradient centrifugation. Apical membranes were isolated from the homogenate by a step- gradient and differential centrifugation. Both samples were then checked for purity via marker enzyme assays. Integral proteins were extracted with Triton-X114. Both membrane proteins and isolated integral membrane proteins were characterized by SDS gel electrophoresis. The results showed six candidate fusion proteins of molecular weight 64.1, 61.7, 56.8, 43.1, 42.1, and 14.8 kDal based on their relative hydrophobicity. Membrane fusogenicity was assessed by monitoring the solubilization of the condensed granule core. Vesicle membranes lack the ability to fuse to one another, but will fuse to the apical plasma membrane. However, on a sample to sample basis, the rate of fusion was not correlated to the absolute concentration of apical plasma membrane. Therefore, apical membrane is apparently required for fusion but it does not control the overall rate. The fusion rate may be regulated by the membrane lipid environemnt as shown by an increase in fusion capacity after arachidonic acid treatment of the apical membrane. However, arachidonic acid did not influence the rate when the vesicular membrane was treated. This points toward an integral membrane protein acting as a docking site for the vesicle with fusion rate possibly being controlled by phospholipase and apical plasma membrane fluidity.
Recommended Citation
Kaufman, Gary, "Characterization of secretory membranes and exocytotic fusion" (1992). Honors Capstones. 280.
https://huskiecommons.lib.niu.edu/studentengagement-honorscapstones/280
Extent
23 unnumbered pages
Language
eng
Publisher
Northern Illinois University
Rights Statement
In Copyright
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.
Media Type
Text
Comments
Includes bibliographical references.