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Full-Text Articles in Cell and Developmental Biology
Possible Molecular Mechanism To Account For Wavelength Dependence Of Equilibration Rates Of Patman And Laurdan In Phosphatidylcholine Bilayers, Hannabeth A. Franchino
Possible Molecular Mechanism To Account For Wavelength Dependence Of Equilibration Rates Of Patman And Laurdan In Phosphatidylcholine Bilayers, Hannabeth A. Franchino
Theses and Dissertations
Patman is a fluorescent membrane probe related to Laurdan. The structural distinctions between the two probes are the lengths of the aliphatic tails (eleven carbons in Laurdan and fifteen in Patman) and the presence of a trimethylammonium group on Patman that produces a positively-charged head. Preliminary studies exploring Patman as a probe to detect membrane properties during apoptosis revealed that the fluorescence intensity of two edges of the emission spectrum (435 and 500 nm) stabilizes at different rates as the probe binds to the cell membrane. To test whether these differences represent dissimilarities in probe binding to ordered and disordered …
Investigating And Modeling Possible Mechanisms By Which Healthy Cell Membranes Become Resistant To Hydrolysis By Secretory Phospholipase A2, Jennifer Nelson
Investigating And Modeling Possible Mechanisms By Which Healthy Cell Membranes Become Resistant To Hydrolysis By Secretory Phospholipase A2, Jennifer Nelson
Theses and Dissertations
Secretory phospholipase A2 (sPLA2) behaves differently toward the membranes of healthy cells compared to those of damaged or dying cells. The enzyme catalyzes rapid and sustained hydrolysis of compromised cells consistent with a simple catalytic mechanism. In contrast, when healthy cells are incubated with sPLA2, they become resistant to hydrolytic attack as manifest by three unusual observations: First, hydrolysis is transient and represents only a small fraction of the total membrane phospholipid content. Second, subsequent addition of sPLA2 fails to generate additional product. Third, the apparent potency of the enzyme to cause the membrane to be refractory is much greater …
The Influence Of Membrane Lipid Order On Cell Shape And Microvesiculation In Human Erythrocytes, Laurie Jackson Gonzalez
The Influence Of Membrane Lipid Order On Cell Shape And Microvesiculation In Human Erythrocytes, Laurie Jackson Gonzalez
Theses and Dissertations
Exposure of human erythrocytes to elevated intracellular calcium causes alterations in cell shape and stimulates shedding of the cell membrane in the form of microvesicles. We hypothesized that both the shape transition and microvesiculation are influenced by microscopic membrane physical properties such as lipid order. To test this hypothesis, membrane properties were manipulated by varying the experimental temperature, membrane cholesterol content, and the internal ionic environment. Changes in membrane order were assessed using steady-state fluorescence spectroscopy with an environment-sensitive probe, laurdan. Our observations led us to the following conclusions: 1) the modest temperature dependence of membrane structure observed with laurdan …