Actinomycetales Raman spectrometry hydrogen bond molecular dynamics Bacterial Proteins Heme Hydrogen Bonding Molecular Dynamics Simulation Protein Binding Spectrum Analysis, Raman Thermobifida fusca Truncated Hemoglobins article heme ligand truncated hemoglobin Active site Catalytic Domain Hemoglobin Hydrogen-Ion Concentration Ligands MES Molecular dynamics Molecular dynamics simulations Mutation PH Porphyrins Recombinant Proteins Wild-type proteins electron spin resonance