caa a22 4500 445326581 CHVBK 20180317142722.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s10989-011-9247-y doi (NATIONALLICENCE)springer-10.1007/s10989-011-9247-y Comparison of the Chaperoning Action of Glycerol and β-Casein on Aggregation of Proteins in the Presence of Crowding Agent [Elektronische Daten] [Arezou Ghahghaei, S. Bathaie, Ali Shahraki, Farzad Rahmany Asgarabad] β-Casein is one of the major components of the milk micelles of most mammals and has been shown to exhibit in vitro chaperone-like activity. Glycerol is a chemical chaperone belonging to the polyol family, which increases protein stability and inhibits protein aggregation. These prompted us to compare the chaperone-like activity of β-casein and glycerol. In this study, the effect of β-casein and glycerol on folding of the target proteins (ovotransferrin, insulin and α-lactalbumin) in the presence of dextran, as a macromolecular crowding agent, is examined using visible absorption spectroscopy, intrinsic fluorescence spectroscopy, 1-anilino-8-naphthalene sulfonic acid fluorescence binding and near CD spectroscopy. In the presence of dextran, the rate and extent of aggregation of target proteins was enhanced and β-casein was less effective in preventing the aggregation and precipitation of target proteins. These data support the hypothesis that β-casein interacts more effectively with slowly aggregating rather than rapidly aggregating target proteins. It is proposed that dextran-induced changes to protein conformation and the rate of intermolecular association are in a kinetic competition with the chaperoning action of β-casein; however our results demonstrated the higher activity of glycerol, as a chemical chaperone, than β-casein on the folding of target proteins, especially in the presence of dextran. This is likely due to the stabilizing effect of glycerol on protein structure and environment. The implications for the in vivo functions of β-casein and glycerol, based on their exhibiting such in vitro chaperone-like activities, are discussed. Springer Science+Business Media, LLC, 2011 β-Casein nationallicence Glycerol nationallicence Molecular chaperone nationallicence Molecular crowding nationallicence Protein aggregation nationallicence ANS : 1-Anilino-8-naphthalene sulfonic acid nationallicence HMM : High molecular mass nationallicence Ghahghaei Arezou Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran aut Bathaie S. Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran aut Shahraki Ali Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran aut Rahmany Asgarabad Farzad Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran aut International Journal of Peptide Research and Therapeutics Springer Netherlands 17/2(2011-06-01), 101-111 1573-3149 17:2<101 2011 17 10989 https://doi.org/10.1007/s10989-011-9247-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10989-011-9247-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ghahghaei Arezou Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran aut NATIONALLICENCE 700 1- Bathaie S. Department of Clinical Biochemistry, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran aut NATIONALLICENCE 700 1- Shahraki Ali Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran aut NATIONALLICENCE 700 1- Rahmany Asgarabad Farzad Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran aut NATIONALLICENCE 773 0- International Journal of Peptide Research and Therapeutics Springer Netherlands 17/2(2011-06-01), 101-111 1573-3149 17:2<101 2011 17 10989 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer