A specific cholesterol binding site is established by the 2.8 Å structure of the human β2-adrenergic receptor in an alternate crystal form

• Published in: Structure (London) 2008-06, Vol.16 (6), p.897-905
• Main Authors: Hanson, Michael A., Cherezov, Vadim, Roth, Christopher B., Griffith, Mark T., Jaakola, Veli-Pekka, Chien, Ellen Y. T., Velasquez, Jeffrey, Kuhn, Peter, Stevens, Raymond C.
• Format: Article
• Language: English
• ISSN: 0969-2126
• DOI: 10.1016/j.str.2008.05.001

The role of cholesterol in eukaryotic membrane protein function has been primarily attributed to an influence on membrane fluidity and curvature. Herein, we present the 2.8 Å resolution crystal structure of a thermally-stabilized human β 2 -adrenergic receptor bound to cholesterol and the partial inverse agonist timolol. The receptors pack as monomers in an antiparallel association with two distinct cholesterol molecules bound per receptor, but not in the packing interface, thereby indicating a structurally relevant cholesterol binding site between helices I, II, III, and IV. Thermal stability analysis using isothermal denaturation confirms that cholesterol significantly enhances the stability of the receptor. A consensus motif is defined that predicts cholesterol binding for 26% of all class A receptors suggesting that specific sterol binding is important to the structure and stability of other G protein-coupled receptors, and that this site may provide a novel target for allosteric therapeutic discovery.