Enhanced heme accessibility in horse heart mini-myoglobin: Insights from molecular modelling and reactivity studies

Polticelli, Fabio; Zobnina, Veranika; Ciaccio, Chiara; Sanctis, Giampiero De; Ascenzi, Paolo; Coletta, Massimo

doi:10.1016/j.abb.2015.09.005

Cited by 3 publications

(2 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The order of magnitude of the values of k on lay within the range of those reported for over 40 hemeprotein systems toward inorganic sulfide (Supporting Information section SI1). Collectively, these results strongly point at a common dissociative mechanism, with the release of the bound water molecule as the rate limiting step of the process. − As stated above, the decrease of k on as a function of pH has been previously reported for Mb-Fe III , ,, for Hb I, II, and III from Lucina pectinata , for Hb from Vitreoscilla , and for human , and porcine hemoglobins …”

Section: Resultsmentioning

confidence: 52%

Mechanism of Sulfide Binding by Ferric Hemeproteins

et al. 2018

View full text Add to dashboard Cite

The reaction of hydrogen sulfide (HS) with hemeproteins is a key physiological reaction; still, its mechanism and implications are not completely understood. In this work, we propose a combination of experimental and theoretical tools to shed light on the reaction in model system microperoxidase 11 (MP11-Fe) and myoglobin (Mb-Fe), from the estimation of the intrinsic binding constants of the species HS and hydrosulfide (HS), and the computational description of the overall binding process. Our results show that HS and HS are the main reactive species in Mb-Fe and MP11-Fe, respectively, and that the magnitude of their intrinsic binding constants are similar to most of the binding constants reported so far for hemeproteins systems and model compounds. However, while the binding of HS to Mb-Fe was negligible, the binding of HS to MP11-Fe was significant, providing a frame for a discriminated analysis of both species and revealing differential mechanistic aspects. A joint inspection of the kinetic data and the free energy profiles of the binding processes suggests that a dissociative mechanism with the release of a coordinated water molecule as rate limiting step is operative in the binding of HS to Mb-Fe and that the binding of HS is prevented in the access to the protein matrix. For the MP11-Fe case, where no access restrictions for the ligands are present, an associative component in the mechanism seems to be operative. Overall, the results suggest that if accessing the active site then both HS and HS are capable of binding a ferric heme moiety.

show abstract

Section: Resultsmentioning

confidence: 52%

Mechanism of Sulfide Binding by Ferric Hemeproteins

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Interestingly, the reaction mechanism shown in Figs 7 and 8 has been used also to describe ligand binding to five-coordinate ferric globins. In fact, most of five-coordinate ferric globins bind a water molecule or a hydroxide ion at the sixth coordination position of the heme-Fe atom, resembling endogenously six-coordinate globins (Ascenzi et al, 2004;Brancaccio et al, 1994;Coletta et al, 1996;Couture et al, 1999;de Sanctis et al, 2007;Hamdane et al, 2003;Hargrove, 2000;Hvitved et al, 2001;Milani et al, 2005;Pesce et al, 2004;Polticelli et al, 2015;Trent and Hargrove, 2002).…”

Section: Neuroglobin Reactivitymentioning

confidence: 99%

Neuroglobin: From structure to function in health and disease

Ascenzi

Masi

Leboffe

et al. 2016

Molecular Aspects of Medicine

Self Cite

145

View full text Add to dashboard Cite

A molecule for all seasons: The heme

Ascenzi

Brunori

2016

J. Porphyrins Phthalocyanines

View full text Add to dashboard Cite

If life without heme-Fe were at all possible, it would definitely be different. Indeed this complex and versatile iron-porphyrin macrocycle upon binding to different “globins” yields hemeproteins crucial to sustain a variety of vital functions, generally classified, for convenience, in a limited number of functional families. Over-and-above the array of functions briefly outlined below, the spectacular progress in molecular genetics seen over the last 30 years led to the discovery of many hitherto unknown novel hemeproteins in prokaryotes and eukaryotes. Here, we highlight a few basic aspects of the chemistry of the hemeprotein universe, in particular those that are relevant to the control of heme-Fe reactivity and specialization, as sculpted by a variety of interactions with the protein moiety.

show abstract

Enhanced heme accessibility in horse heart mini-myoglobin: Insights from molecular modelling and reactivity studies

Cited by 3 publications

References 34 publications

Mechanism of Sulfide Binding by Ferric Hemeproteins

Mechanism of Sulfide Binding by Ferric Hemeproteins

Neuroglobin: From structure to function in health and disease

A molecule for all seasons: The heme

Contact Info

Product

Resources

About