title: Sulfmyoglobin Conformational Change: A Role in the Decrease of Oxy-Myoglobin Functionality.
abstract: This work is focused at understanding the interaction of H2S with Myoglobin (Mb), in particular the Sulfmyoglobin (SMb) product, whose physiological role is controversial and not well understood. The scattering curves, Guinier, Kratky, Porod and P(r) plots were analyzed for oxy-Mb and oxy-Hemoglobin I (oxyHbI) in the absence and presence of H2S, using Small and Wide Angle X-ray Scattering (SAXS/WAXS) technique. Three dimensional models were also generated from the SAXS/WAXS data. The results show that SMb formation, produced by oxyMb and H2S interaction, induces a change in the protein conformation where its envelope has a very small cleft and the protein is more flexible, less rigid and compact. Based on the direct relationship between Mb's structural conformation and its functionality, we suggest that the conformational change observed upon SMb formation plays a contribution to the protein decrease in O2affinity and, therefore, on its functionality.
authors.affiliation: Department of Chemistry, University of Puerto Rico, Mayagüez Campus, PO BOX 9019, Mayagüez, Puerto Rico 00681-9019.
authors.forename: Elddie
authors.initials: E
authors.lastname: Román-Morales
authors.affiliation: Department of Chemistry, University of Puerto Rico, Mayagüez Campus, PO BOX 9019, Mayagüez, Puerto Rico 00681-9019.
authors.forename: Erika
authors.initials: E
authors.lastname: López-Alfonzo
authors.affiliation: Department of Chemistry, University of Puerto Rico, Mayagüez Campus, PO BOX 9019, Mayagüez, Puerto Rico 00681-9019.
authors.forename: Ruth
authors.initials: R
authors.lastname: Pietri
authors.affiliation: Department of Chemistry, University of Puerto Rico, Mayagüez Campus, PO BOX 9019, Mayagüez, Puerto Rico 00681-9019.
authors.forename: Juan
authors.initials: J
authors.lastname: López-Garriga
keywords: SAXS; WAXS; hemoglobin I (HbI); hydrogen sulfide (H2S); myoglobin (Mb); sulfmyoglobin (SMb)