Microsolvation Effect on the Twist of beta-sheets

作者：Ireta Joel^*

来源：Journal of Chemical Theory and Computation, 2011, 7(8): 2630-2637.

DOI：10.1021/ct2002144

Under certain circumstances beta-sheets prefer to be twisted instead of flat. To get insight into the reasons of such preference, bare and microsolvated parallel and antiparallel two-strand polyalanine beta-sheets are investigated using density functional theory. Full geometry optimizations show that microsolvation increases interstrand twisting and promotes a flat to twist transition. It is found that the latter behavior is connected to compressive strain resulting from microsolvation. Residues in flat beta-sheets adjust the sense of its local intrastrand twist, which leads to the appearance of interstrand twist, to release strain and to favor water-water hydrogen bonding. The predicted microsolvation effect is corroborated analyzing the geometry of residues forming beta-sheet motifs in protein crystals.

• 出版日期2011-8