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On the Pathways of Biologically Relevant Diatomic Gases through Proteins. Dioxygen and Heme Oxygenase from the Perspective of Molecular Dynamics
Author(s) -
Pietra Francesco
Publication year - 2013
Publication title -
chemistry and biodiversity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 70
eISSN - 1612-1880
pISSN - 1612-1872
DOI - 10.1002/cbdv.201200434
Subject(s) - myoglobin , chemistry , diatomic molecule , heme , hemeprotein , binding site , protein dynamics , heme oxygenase , molecular dynamics , active site , stereochemistry , biophysics , biochemistry , computational chemistry , molecule , catalysis , enzyme , biology , organic chemistry
This work deals with dioxygen (O 2 ) binding sites and pathways through inducible human heme oxygenase (HO‐1). The experimentally known distal binding site 1, and sites 2–3 above it, could be reproduced by means of non‐deterministic random‐acceleration molecular‐dynamics (RAMD) simulations. In addition, RAMD revealed the proximal binding site 5, a deeply‐seated binding site 4, which lies behind heme, as well as a few gates communicating with the external medium. In getting from site 1 to the main gate, which lies on the protein front opposed to site 4, O 2 follows chiefly the shortest direct pathway. Less frequently, O 2 visits intermediate sites 2, 4, or 5 along longer pathways. A similarity between HO‐1, myoglobin, and cytoglobin in using, for diatomic gas delivery, the direct shortest pathway from the heme center to the surrounding medium, is emphasized. Otherwise, comparing other proteins and diatomic gases, each system reveals its peculiarities as to sites, gates, and pathways. Thus, relating these properties to the physiological functions of the proteins remains in general a challenge for future studies.