Descripción estadística del proceso de plegamiento del lazo 36 de la cadena AH2 de la Hemaglutinina

Abstract

In this work, we studied the transition of Hemagglutinin’s loop-36 between its non-fusogenic and fusogenic states, with a statistical mechanics approach. The initial sampling of the conformational space between this states, performed through a TMD simulation, found 11 intermediate groups (pseudo-conformations). They were the “seed” of the properly called conformations, of which we identified 321 in total. Along the TMD trajectory, we found an “entropic well” with an associated energy of 1.2 kcal/mol, as well as an enthalpic barrier of (279.93± 34.41) kcal/mol. The constructed potential-energy landscape is a rugged surface with 2 pronounced minimums and equipotential lines associated to different pseudo-conformations, which suggests the possibility of natural transitions between conformations explored by them. We proposed 16 transitions, based on the information contained in the first 2 principal components (48.36% of the data variance), the gyration radius and the RMSD of the structures.