A system was developed to study membrane transport in isolated human fibroblast plasma membrane vesicles, avoiding potential complications of intracellular binding and metabolism in the intact cell. Ten-fold enrichment of plasma membranes after subcellular fractionation was confirmed with appropriate markers. Transport competence was established by the following criteria: osmotic sensitivity, stereospecificity, temperature dependence, sodium gradient stimulation, response to ions and ionophores, saturability, and exchange properties. Methotrexate uptake was osmotically sensitive, temperature sensitive, saturable, and inhibited by folinic acid and phosphate. Measurement of lysine uptake was complicated by binding and lack of sodium dependence, but was stimulated by an interior-negative membrane potential, and intravesicular lysine or arginine. Exchange properties of the lysine carrier were exploited to assess its function in fibroblasts from patients with the Mendelian phenotype, lysinuric protein intolerance (LPI). LPI vesicles were not different from controls in their lysine transport phenotype.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.71945 |
| Date | January 1984 |
| Creators | Buchanan, Janet Ann. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000215698, proquestno: AAINK66693, Theses scanned by UMI/ProQuest. |
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