caa a22 4500 397556306 CHVBK 20180308164803.0 cr unu---uuuuu 161202e199606 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021360 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021360 Dual Roles of DMPC and CHAPS in the Refolding of Bacterial Opsins In Vitro [Elektronische Daten] [Yasuo Sugiyama, Yasuo Mukohata] The bacterial opsins can be refolded to regenerate the chromophore by transfer from SDS to DMPC/CHAPS/SDS mixed micelles in the presence of retinal. A sequential refolding model has been proposed for bacterioopsin [Booth et al. (1995) Nature Struct Biol. 2, 139-143]. However, the roles of DMPC and CHAPS in the refolding process are not clear. In this study we measured the effects of DMPC and CHAPS on the refolding of bacterial opsins in vitro by CD and fluorescence spectroscopy. In contrast to in experiments in the presence of large amounts of DMPC, the process of retinal binding pocket formation was a rate-determining step in overall chromophore regeneration with relatively low concentrations of DMPC. CHAPS triggered α-helix formation and long-range interactions between the helices within 1 s by providing a suitable hydrophobic environment for bacterial opsins. This CHAPS-induced transient molten globule-like structure would be identical to I1 postulated by Booth et al., to which DMPC bound and induced the proper packing of the side chains to form a retinal binding pocket. If DMPC was not present, CHAPS induced another conformation change in bacterial opsins, which led to denaturation. DMPC dependence of chromophore regeneration and the maintenance of the retinal binding pocket suggested that retinal binding pocket formation was part of the large structure changes during stable apoprotein formation. © by the Journal of Biochemistry Regular Papers nationallicence archaeopsin nationallicence bacterioopsin nationallicence long-range interaction nationallicence refolding process in vitro nationallicence retinal binding pocket nationallicence Sugiyama Yasuo Department of Biology, School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-01 aut Mukohata Yasuo Department of Biology, School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-01 aut The Journal of Biochemistry Oxford University Press 119/6(1996-06), 1143-1149 0021-924X 119:6<1143 1996 119 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021360 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021360 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sugiyama Yasuo Department of Biology, School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-01 aut NATIONALLICENCE 700 1- Mukohata Yasuo Department of Biology, School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-01 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 119/6(1996-06), 1143-1149 0021-924X 119:6<1143 1996 119 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford