title: Oxygen affinity controlled by dynamical distal conformations: the soybean leghemoglobin and the Paramecium caudatum hemoglobin cases.
abstract: The binding of diatomic ligands, such as O(2), NO, and CO, to heme proteins is a process intimately related with their function. In this work, we analyzed by means of a combination of classical Molecular Dynamics (MD) and Hybrid Quantum-Classical (QM/MM) techniques the existence of multiple conformations in the distal site of heme proteins and their influence on oxygen affinity regulation. We considered two representative examples: soybean leghemoglobin (Lba) and Paramecium caudatum truncated hemoglobin (PcHb). The results presented in this work provide a molecular interpretation for the kinetic, structural, and mutational data that cannot be obtained by assuming a single distal conformation.
authors.affiliation: Departamento de Química Inorgánica, Analítica y Química Física INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Martí
authors.forename: Luciana
authors.initials: L
authors.lastname: Capece
authors.forename: Damián E
authors.initials: DE
authors.lastname: Bikiel
authors.forename: Bruno
authors.initials: B
authors.lastname: Falcone
authors.forename: Darío A
authors.initials: DA
authors.lastname: Estrin
mesh_terms: D000818:Animals; D001665:Binding Sites; D003198:Computer Simulation; D006454:Hemoglobins / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D007874:Leghemoglobin / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D010100:Oxygen / Q000378:metabolism*; D048488:Paramecium caudatum / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D015800:Protozoan Proteins / Q000737:chemistry* / Q000378:metabolism; D013025:Glycine max / Q000378:metabolism; D054793:Truncated Hemoglobins
chemical_list: D006454:Hemoglobins; D007874:Leghemoglobin; D010940:Plant Proteins; D015800:Protozoan Proteins; D054793:Truncated Hemoglobins; D010100:Oxygen