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Title: Covalent modifications of eye lens proteins by oxidation and glycation
Researcher: Luthra, Manni.
Guide(s): Balasubramanian, D
Keywords: Molecular Biology
Cellular Biology
eye lens proteins
Upload Date: 13-Jan-2014
University: Jawaharlal Nehru University
Completed Date: 1993
Abstract: The normal mammalian eye lens is a transparent body made up of long newlineenucleated fiber-shaped· cells of epithelial origin which, during differentiation, rid newlinethemselves of large organelles that are likely to scatter light, and overexpress structural newlineproteins called the crystallins to very high intracellular concentrations [200 - 500 newlinemg/ml]. These highly concentrated crystallin solutions achieve a minimization of lightscattering newlinethrough a short-range ordering of molecules into a glass-like state. A newlinereduction in light-scattering is also achieved through a neat inter-cellular stacking of the newlinehexagonally cross-sectioned fiber cells. Thus, the lens owes its transparency, as well newlineas its other optical properties (such as the existence of a smooth radial refractive newlinegradient), to the ordered organization of its constituents. newlineChanges in such molecular ordering, arising from protein conformational newlinecharrges, aggregation and precipitation, bring about an increase in light-scattering newlinethrough both direct scattering of light from particulate protein matter, as well as newlinethrough scattering effected by discontinuities generated in the radial refractive newlinegradient. Such changes tend to be permanent, on account of the fact that lens cells newlinedegrade their nuclei early in development and cannot, therefore, tum over their newlinemolecules. With increase in age, the transmission of light by the lens decreases, newlineespecially at the lower wavelengths. This decrease in transmission is reflected in the newlineincreasing opacity of the lens, in a condition known as cataract. There are several newlinecausal factors for the onset of cataract, primary among these being the processes of newlineoxidation and glycation. newlineWith aging and chronic oxidative stress, crystallins undergo covalent chemical newlinemodifications leading to formation of high molecular weight aggregates, insoluble newlineiv newlineprotein particles and increased pigmentation.
Pagination: ix,207p.
Appears in Departments:Centre for Molecular and Cellular Biology

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01_title.pdfAttached File19.31 kBAdobe PDFView/Open
02_dedication.pdf9.64 kBAdobe PDFView/Open
03_certificate.pdf19.64 kBAdobe PDFView/Open
04_acknowledgements.pdf78.94 kBAdobe PDFView/Open
05_contents.pdf112.63 kBAdobe PDFView/Open
06_abbreviation.pdf54.44 kBAdobe PDFView/Open
07_abstract.pdf162.64 kBAdobe PDFView/Open
08_publication.pdf24.54 kBAdobe PDFView/Open
09_chapter 1.pdf534.7 kBAdobe PDFView/Open
10_chapter 2.pdf1.29 MBAdobe PDFView/Open
11_chapter 3.pdf368.46 kBAdobe PDFView/Open
12_chapter 4.pdf473.37 kBAdobe PDFView/Open
13_chapter 5.pdf1.95 MBAdobe PDFView/Open
14_references.pdf362.51 kBAdobe PDFView/Open

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