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International Journal of Diabetes & Clinical Diagnosis Volume 2 (2015), Article ID 2:IJDCD-109, 8 pages
http://dx.doi.org/10.15344/2394-1499/2015/109
Research Article
Ammonium Sulfate Precipitation but Not Delipidation is a Valuable Method for Human Albumin Preparation for Biological Studies

Jennifer Baraka-Vidot, Indira Denemont, Zainabou Ali Mcolo, Emmanuel Bourdon, Philippe Rondeau*

Inserm, UMR 1188 Diabète athérothrombose Thérapies Réunion Océan Indien (DéTROI) , Université de La Réunion, Plateforme CYROI, 2 Rue Maxime Rivière, BP 80 005, 97491 Sainte Clotilde Cedex, Reunion Island, France
Dr. Philippe Rondeau, Inserm, UMR 1188 Diabète athérothrombose Thérapies Réunion Océan Indien (DéTROI) , Université de La Réunion, Plateforme CYROI, 2 Rue Maxime Rivière, BP 80 005, 97491 Sainte Clotilde Cedex, Reunion Island, France; E-mail: rophil@univ-reunion.fr
26 December 2014; 17 February 2015; 19 February 2015
Baraka-Vidot J, Denemont I, Ali Mcolo Z, Bourdon E, Rondeau P (2015) Ammonium Sulfate Precipitation but Not Delipidation is a Valuable Method for Human Albumin Preparation for Biological Studies. Int J Diabetes Clin Diagn 2: 109. doi: http://dx.doi.org/10.15344/2394-1499/2015/109
This work was supported by the Ministère de l’Enseignement Supérieure et de la Recherche, the Ministère de l’Outre-Mer, the Conseil Régional de La Réunion and Europe, the Université de La Réunion and the fédération Environnement Biodiversité Santé- FED4126. JBV was supported by a fellowship from the Conseil Régional de La Réunion and Europe.

Abstract

Background: Glycated hemoglobin level is considered as one of the main clinical parameters used for diabetes diagnosis. With a shorter half-life than hemoglobin, glycated human serum albumin appears to be an alternative and relevant marker for glycemic control and for the diagnosis of numerous associateddiabetes complications. The characterization of albumin as an alternative marker in clinical studies required its delipidation after the protein purification from plasma. The aim of this study was to find a reliable and convenient method for albumin delipidation and purification which does not have significant impact on the redox state, intrinsic structural and functional integrities of human serum albumin.
Methods: Affinity chromatography and ammonium sulfate precipitation were the two different techniques used for albumin isolation from plasma and delipidation was performed with ethanol-ether mixture. The biochemical (redox state), structural and functional (antioxidant, affinity and esterase properties) integrities of purified HSA were determined by using biochemical assays and fluorescence spectroscopy measurements.
Results: The two-step precipitation of HSA with ammonium sulfate enabled to purify albumin exhibiting preserved structural and functional properties in terms of antioxidant and enzymatic activity and through a rapid and efficient protocol. By contrast, batch- or chromatography affinity-mediated purification presented more backwards than ammonium sulfate precipitation method. In addition, our results showed the delipidation step following the purification should not to be considered as it impacted both structure and function of albumin.
Conclusion: Such novel insights may in turn unlock novel protocol developments that should help reach a better understanding of modified albumin involvement in insulin resistance progression.