Fig. 2: HBS between PPII helices in the different interfaces of the computational model at the M06-2X/6-31 + G(d) level of theory.
From: Hydrogen bonding patterns and cooperativity in polyproline II helical bundles
The ab interface is indicated in blue; the bc interface, in red, and the cd interface, in yellow, as the color scheme depicted in Fig. 1C. Note that the HBS values decrease significantly as more PPII helices are added; this is a hallmark of HBC.
