Membrane matters: The impact of a nanodisc-bilayer or a detergent microenvironment on the properties of two eubacterial rhodopsins

Dissecting lipid contents in the distinct regions of native retinal rod disk membranes

“…The regenerated samples were stable and soluble for days at room temperature. These results highlight the ability of SMALPs to efficiently extract this model GPCR in a stable form from its native, mammalian tissue, as has been done in cell lines and lower species with other GPCRs (Jamshad et al, 2015;Gakhar et al, 2020;Ganapathy et al, 2020;Bada Juarez et al, 2020;Routledge et al, 2020;Ueta et al, 2020).…”

“…The current lack of knowledge regarding molecular differences between the center and rim of ROS disk membranes represents a significant bottleneck in the study of lipid synthesis, metabolism, and transport (Zhang et al, 2001;Edwards et al, 2001;Chen et al, 2005Chen et al, , 2007Berdeaux et al, 2010;Sapieha et al, 2011;Chen et al, 2013Chen et al, , 2020. These processes modulate the impact of lipids on retinal degenerative diseases, such as Stargardt-like macular dystrophy type 3, retinitis pigmentosa, diabetic retinopathy, and age-related macular degeneration (Simonelli et al, 1996;Bernstein et al, 2001;Seddon, 2003Seddon, , 2006SanGiovanni et al, 2007;Liu et al, 2010;Tikhonenko et al, 2010Tikhonenko et al, , 2013Logan et al, 2013;Logan and Anderson, 2014;Hiebler et al, 2014).…”

Applicability of Styrene-Maleic Acid Copolymer for Two Microbial Rhodopsins, RxR and HsSRI

“…In this study, we used RxR and HsSRI to evaluate the applicability of SMA forming a membrane-mimicking assembly for microbial rhodopsins. Previous studies have applied SMA so far to several microbial rhodopsins, such as H. salinarum bacteriorhodopsin, Natronomonas pharaonis sensory rhodopsin II (NpSRII), and proteorhodopsin (30)(31)(32)(33). We will fully discuss the results and applicability of SMA estimated in this study in comparison with the previous studies.…”

“…For the preparation of SMA, a styrene-maleic anhydride (SMAnh) copolymer (SMA2000, in which the ratio of styrene and maleic anhydride is $2:1; Cray Valley, Exton, PA) was kindly provided by Kawahara Petrochemical (Osaka, Japan). The copolymer has been widely used to characterize several membrane proteins in the previous studies (19,33). The number average molecular weight, weight average molecular weight, and polydispersity index were 3000, 7500, and 2.5, respectively.…”

Methods for the solubilisation of membrane proteins: the micelle-aneous world of membrane protein solubilisation

“…MSP nanodiscs present an attractive biochemical tool considering their tunable size, lipid composition and tagging capabilities hence their applications are numerous and continue to grow. A sample of MSP nanodisc applications include binding experiments (surface plasmon resonance [ 42 ], localised surface plasmon resonance [ 43 ]), fractionation methods (electrophoresis [ 44 ], ultracentrifugation [ 45 ], chromatography [ 46 ]), spectroscopic studies [ 47 ] and structural determination (NMR [ 48 ]), X-ray crystallography [ 49 ], electron microscopy [ 50 ], small-angle x-ray scattering [ 51 ], small-angle neutron scattering [ 52 ], analytical ultracentrifugation [ 53 ], neutron reflectometry [ 54 ] highlighting their diverse potential.…”