ЭЛЕКТРОСТАТИЧЕСКОЕ ВЗАИМОДЕЙСТВИЕ ГЛОБИНОВ С ФОСФОЛИПИДНЫМИ МЕМБРАНАМИ

Abstract

The present study aimed to analyze the role of electrostatic interactions contributing to the stability of the native conformations of the heme group in the structure of sperm whale myoglobin (SWMb), horse heart myoglobin (HHMb), hemoglobin I (HbI) from the botfly Gasterophilus intestinalis (giHbI) and monomeric and dimeric hemoglobins HbI and HbII from the mollusk Lucina pectinata (lpHbI and lpHbII) as well as investigate a possible reason of destabilization due to interaction with negatively charged phospholipid membranes. It was shown that the native conformation of the heme cavity in these globins, both in its proximal and distal sides, is sustained by a system of hydrogen bonds involving the proximal and distal protein residues, both heme propionic acid groups and the nearby polar amino acids on the protein surface (His, Arg, Lys). The hydrogen bond network in the proximal part of the heme pocket controls the position of the Fe atom outside or in the protoporphyrin plane, affecting the efficiency of ligand binding, while in the distal part of the heme cavity the hydrogen bond network formed with the participation of the distal protein residue (HisE7 in swMb, hhMb and giHbI, and GlnE7 in lpHbII) should, apparently, stabilize conformation where the protein is able to donate hydrogen to O2 ligand...