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作者 Simard, Jeffrey Raymond
書名 Fatty acid transport: Binding to human serum albumin and trafficking in model and biological membranes
國際標準書號 9780542285219
book jacket
說明 429 p
附註 Source: Dissertation Abstracts International, Volume: 66-08, Section: B, page: 4121
Major Professor: James A. Hamilton
Thesis (Ph.D.)--Boston University, 2006
Long chain fatty acids (LCFA) are important dietary nutrients but also play a role in the onset and pathology of obesity and diabetes. This study (i) characterized the binding of LCFA to human serum albumin (HSA) by 13C NMR and (ii) elucidated the primary mechanism of fatty acid (FA) transport across biological membranes by fluorescence spectroscopy
The binding of LCFA to albumin has been studied for decades without identification of the highest affinity FA binding sites. 13C NMR was used to study the binding of 13C-palmitate to HSA, its isolated domain III and site-specific mutants of HSA. Additionally, site-specific displacement of FA using drugs that share binding site(s) with FA was studied. Specific changes in FA chemical shifts in mutants and in drug/HSA complexes were correlated with the individual binding sites, previously revealed in the x-ray crystal structure. The NMR peaks corresponding to all LCFA binding sites were identified
A novel assay was developed to measure FA binding to membranes. Using acceptor phospholipid vesicles labeled with a probe that detects FA incorporation into the hydration surface of phospholipids (fluorescein-phosphatidylethanolamine), the adsorption and desorption of oleate that was delivered uncomplexed or bound to donor vesicles or bovine serum albumin (BSA) was measured. The rate constants were significantly different for each donor system and indicated that desorption from the donor was the slowest step of FA diffusion
Finally, to clarify roles of membrane proteins in FA transport, FA transport across membranes of adipocytes treated with proposed FA transport inhibitors was investigated. In addition, FA transport was studied in an engineered HEK cell line with differing amounts of a putative FA transporter, caveolin-1. Most inhibitors did not affect FA transport through model membranes (phospholipid bilayers) or the plasma membrane of rat adipocytes. Some inhibitors produced artifacts unrelated to protein inhibition. It was concluded that (i) FA diffusion was the primary mechanism of FA transport into adipocytes and HEK cells and (ii) FA metabolism or binding to putative transport proteins (such as caveolin-1 at the inner leaflet) maintains a gradient that enhances bulk diffusion of FA
School code: 0017
DDC
Host Item Dissertation Abstracts International 66-08B
主題 Health Sciences, Pharmacology
Biology, Animal Physiology
Biophysics, General
0419
0433
0786
Alt Author Boston University
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