1 ‡Department of Biochemistry, Microbiology and Bioinformatics, Université Laval, Québec, Québec, Canada.
2 ?Centre for Research in Molecular Modeling (CERMM), Concordia University, Montréal, Québec, Canada.

A singular aspect of the 2-on-2 hemoglobin structures of groups I and II is the presence of tunnels linking the protein surface to the distal heme pocket, supporting the storage and the diffusion of small apolar ligands to/from the buried active site. As the solubility of apolar ligands is greater in biological membranes than in solution, the association of these proteins with biological membranes may improve the efficiency of ligand capture. As very little is known on this subject, we have...