» Articles » PMID: 35628258

The Val34Met, Thr164Ile and Ser220Cys Polymorphisms of the β2-Adrenergic Receptor and Their Consequences on the Receptor Conformational Features: A Molecular Dynamics Simulation Study

Overview
Journal Int J Mol Sci
Publisher MDPI
Date 2022 May 28
PMID 35628258
Authors
Affiliations
Soon will be listed here.
Abstract

The gene encoding the β2-adrenergic receptor (β2-AR) is polymorphic, which results in possible differences in a primary structure of this protein. It has been shown that certain types of polymorphisms are correlated with some clinical features of asthma, including airways reactivity, whereas the influence of other is not yet understood. Among polymorphisms affecting amino acids at positions 16, 27, 34, 164 and 220, the latter three are present in the crystal structure of β2-AR, which facilitates studying them by means of molecular dynamics simulations. The current study was focused on investigating to what extent the three polymorphisms of β2-AR (i.e., Val34Met, Thr164Ile and Ser220Cys) affect the interaction of β2-AR with its natural molecular environment which includes: lipid bilayer (in the case of all three polymorphs) and Gs protein (which participates in β2-AR-mediated signaling; in the case of Ser220Cys). We have designed and carried out a series of molecular dynamics simulations at different level of resolution (i.e., either coarse-grained or atomistic simulations), accompanied by thermodynamic integration protocol, in order to identify potential polymorphism-induced alterations in structural, conformational or energetic features of β2-AR. The results indicate the lack of significant differences in the case of energies involved in the β2-AR-lipid bilayer interactions. Some differences have been observed when considering the polymorphism-induced alterations in β2-AR-Gs protein binding, but their magnitude is also negligible in relation to the absolute free energy difference correlated with the β2-AR-Gs affinity. The Val34Met and Thr164Ile polymorphisms are weakly correlated with alteration of the conformational features of the receptor around polymorphic sites. On the contrary, it has been concluded that the Ser220Cys polymorphism is correlated with several structural alterations located in the intracellular region of β2-AR, which can induce G-protein binding and, subsequently, the polymorphism-correlated therapeutic responses. More precisely, these alterations involve vicinity of intracellular loops and, in part, are the direct consequence of disturbed interactions of Ser/Cys220 sidechain within 5th transmembrane domain. Structurally, the dynamic structure exhibited by the β2-AR polymorph is closer to the Gs-compatible structure of β2-AR.

References
1.
Deupi X, Kobilka B . Energy landscapes as a tool to integrate GPCR structure, dynamics, and function. Physiology (Bethesda). 2010; 25(5):293-303. PMC: 3056154. DOI: 10.1152/physiol.00002.2010. View

2.
Monticelli L, Kandasamy S, Periole X, Larson R, Tieleman D, Marrink S . The MARTINI Coarse-Grained Force Field: Extension to Proteins. J Chem Theory Comput. 2015; 4(5):819-34. DOI: 10.1021/ct700324x. View

3.
Bruck H, Leineweber K, Beilfuss A, Weber M, Heusch G, Philipp T . Genotype-dependent time course of lymphocyte beta 2-adrenergic receptor down-regulation. Clin Pharmacol Ther. 2003; 74(3):255-63. DOI: 10.1016/S0009-9236(03)00188-7. View

4.
Green S, Turki J, Innis M, Liggett S . Amino-terminal polymorphisms of the human beta 2-adrenergic receptor impart distinct agonist-promoted regulatory properties. Biochemistry. 1994; 33(32):9414-9. DOI: 10.1021/bi00198a006. View

5.
Plazinska A, Plazinski W, Jozwiak K . Agonist binding by the β2-adrenergic receptor: an effect of receptor conformation on ligand association-dissociation characteristics. Eur Biophys J. 2015; 44(3):149-63. PMC: 4359354. DOI: 10.1007/s00249-015-1010-4. View