Please use this identifier to cite or link to this item:
|Title:||Rapid isolation of low density lipoproteins in a concentrated fraction free from water-soluble plasma antioxidants||Authors:||Vieira, Otília V.
Laranjinha, João A.
Madeira, Vítor M.
Almeida, Leonor M.
|Keywords:||Ultracentrifugation; a-tocopherol; Oxidation studies||Issue Date:||Dec-1996||Publisher:||Lipid Research, Inc.||Citation:||Journal of Lipid Research. 37:12 (1996) 2715-2721||Abstract:||A rapid method is described for isolation and concentration of plasma low density lipoproteins (LDL) using a Beckman L80 ultracentrifuge equipped with a 70.1 Ti fixed angle rotor. The isolation of LDL achieved by a discontinuous gradient density step (180 min) was followed by a simultaneous purification and concentration step (45 min) using ultrafiltration through a collodium bag under nitrogen. This dialysis/concentration step, in contrast to the standard dialysis techniques in batch or by filtration through short gel columns, prevents oxidation and dilution of the sample. Electrophoresis in agarose and sodium dodecylsulfate-polyacrylamide (SDS-PAGE) gels were used to monitor LDL surface charge, purity, and contamination with plasma proteins. The artifactual oxidation of LDL during isolation and subsequent handling, and thus the ability of LDL preparation for oxidation/antioxidation studies, was assessed by the determination of endogenous hydroperoxides and thiobarbituric acid reactive substances. The dialysis/concentration step by ultrafiltration that allows the obtention of a concentrated and purified LDL preparation was validated by the absence of ascorbate and urate, as measured by HPLC. This method led to LDL preparations free of water-soluble plasma antioxidants that were minimally oxidized and suitable for reliable in vitro LDL oxidation and inhibition studies. The applicability of this methodology was tested by studying the alpha-tocopherol content of LDL in a Portuguese population of university students||URI:||http://hdl.handle.net/10316/12736||ISSN:||0022-2275||Rights:||openAccess|
|Appears in Collections:||FFUC- Artigos em Revistas Internacionais|
Show full item record
Files in This Item:
|Rapid isolation of low density.pdf||1.5 MB||Adobe PDF||View/Open|
Page view(s) 50422
checked on Mar 23, 2020
checked on Mar 23, 2020
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.