Natascia Sciamanna

TL;DR: It is observed that the rate of ligand dissociation in stopped-flow kinetic measurements progressively increases upon substitution of the H-bonding amino acids, indicating the prevalent interactions at the active site of heme proteins.

TL;DR: A truncated hemoglobin of microbial origin (Thermobifida fusca) investigated in the present work, displays the specific spectroscopic signature of a peroxidase, in agreement with the presence of strong H-bonding residues, i.e., tyrosine and tryptophan, within the distal pocket.

TL;DR: It is shown that H-bonding interactions both with distal residues and water molecules are important structural determinants in the active site of Tf-trHb, and that both the RR Fe-OH(-) and Fe-CN(-) frequencies are very sensitive to the distal environment.

TL;DR: The analysis of the free CO band-shape and of its dynamic evolution brings out novel features about the nature of the docking site inside the protein cavity, which can be interpreted in terms of a different structural flexibility of the corresponding heme distal pockets.

TL;DR: The results indicate a clear structural and dynamical role of a key residue for thermal stability in truncated hemoglobins, and observe that the ProE3 alters the structure of the CD loop, making it more flexible.