Cholesterol increases kinetic, energetic, and mechanical stability of the human β₂-adrenergic receptor

Abstract

The steroid cholesterol is an essential component of eukaryotic membranes, and it functionally modulates membrane proteins, including G protein-coupled receptors. To reveal insight into how cholesterol modulates G protein-coupled receptors, we have used dynamic single-molecule force spectroscopy to quantify the mechanical strength and flexibility, conformational variability, and kinetic and energetic stability of structural segments stabilizing the human β 2 -adrenergic receptor (β 2 AR) in the absence and presence of the cholesterol analog cholesteryl hemisuccinate (CHS). CHS considerably increased the kinetic, energetic, and mechanical stability of almost every structural segment at sufficient magnitude to alter the structure and functional relationship of β 2 AR. One exception was the structural core segment of β 2 AR, which establishes multiple ligand binding sites, and its properties were not significantly influenced by CHS.atomic force microscopy | energy landscape | intermolecular and intramolecular interactions | proteoliposomes

Why have cholesterol and saturated fatty acids acquired proinflammatory roles during evolution? – A hypothesis from atomistic simulations showing sequence-nonspecific stabilization of peptide dimers in lipid raft-like bilayers

“…Unexpectedly, scenario 2) was seen to be the case. This conclusion was supported by our additional analysis using the I(VI) 10 peptide with the 1:1:1 bilayer as well as by that using the poly-Ile peptide with the 2:1:1 bilayer.…”

“…In the case of the β−2 adrenergic receptor, cholesterol is likely to facilitate interaction between G proteincoupled receptors (GPCRs) [8]. Hanson and colleagues presented an X-ray crystallography model of human β−2 adrenergic receptor in which cholesterol is accommodated in the groove formed by four transmembrane (TM) α-helices [9] Using atomic force microscopybased single-molecule force spectroscopy, Zocher et al [10] for example, showed that cholesterol (cholesteryl hemisuccinate was used) considerably augmented the strength of interactions stabilizing structural segments of the β−2 adrenergic receptor. Besides GPCRs, the ability of cholesterol to modulate activities of several ion channels and transporters, including Na+, K+-ATPase, is well-established, as discussed in Lange et al [5].…”

Intramolecular allosteric communication in dopamine D2 receptor revealed by evolutionary amino acid covariation

“…A backbone hydrogen bond links L379F 6.41 and the G protein interacting residue L375 6.37 (V331 6.37 in D3R) (46) (Fig. S6E) (59) and GPCR dimerization (57,60). The equivalent residue to Y213 5.62 in activated β 2 adrenergic receptor (46) stabilizes the "outward" movement of TM6 through a van der Waals contact, consistent with effects of Y213I 5.62 on G protein coupling.…”

GXXXG‐Mediated Parallel and Antiparallel Dimerization of Transmembrane Helices and Its Inhibition by Cholesterol: Single‐Pair FRET and 2D IR Studies

“…[7][8][9][10] Singlemolecule and ensemble methods, such as fluorescence, atomic force microscopy, and NMR, have enabled the observation of membrane protein dynamics in model membranes and living cells. [11][12][13] However, while the existence of dynamics has been established, obtaining specific structural information is difficult in membrane-bound systems, obscuring the link between structure and dynamics.…”