Ligand migration Molecular dynamics Mycobacterium tuberculosis article molecular dynamics nonhuman oxygen affinity priority journal protein function unclassified drug Bacterial Proteins Crystallography, X-Ray Jarzynski Ligands M. tuberculosis Mutant Proteins Nitric oxide Thermodynamics Truncated Hemoglobins Truncated hemoglobin X ray crystallography bioinformatics computer simulation conformational transition crystal structure defense mechanism deoxy truncated hemoglobin n diffusion dioxygenase heme