Structural and thermodynamic basis of proline-induced transmembrane complex stabilization.

ABSTRACT: In membrane proteins, proline-mediated helix kinks are indispensable for the tight packing of transmembrane (TM) helices. However, kinks invariably affect numerous interhelical interactions, questioning the acceptance of proline substitutions and evolutionary origin of kinks. Here, we present the structural and thermodynamic basis of proline-induced integrin αIIbβ3 TM complex stabilization to understand the introduction of proline kinks in membrane proteins. In phospholipid bicelles, the A711P substitution in the center of the β3 TM helix changes the direction of adjacent helix segments to form a 35 ± 2° angle and predominantly repacks the segment in the inner membrane leaflet due to a swivel movement. This swivel repacks hydrophobic and electrostatic interhelical contacts within intracell

SUBMITTER: Schmidt T 

PROVIDER: S-EPMC4951694 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature