A combined EPR and X-ray crystallography approach to the reactivity of hemichromes
Antarctic fish hemoglobins (AFHbs) exhibit a peculiar oxidation process. Indeed, upon oxidation, these tetrameric proteins show a remarkable propensity to evolve toward the formation of a bis-hystidine complex, hemichrome, [1,2]. The crystal structures of the oxidized AFHbs, isolated from Trematomus...
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ftunivnapoliiris:oai:www.iris.unina.it:11588/307848 2024-06-23T07:46:30+00:00 A combined EPR and X-ray crystallography approach to the reactivity of hemichromes VERGARA, ALESSANDRO MERLINO, ANTONELLO FRANZESE, MARISA MAZZARELLA, LELIO G. Di Prisco C. Verde J. Peisach C. Lee Vergara, Alessandro Merlino, Antonello Franzese, Marisa G., Di Prisco C., Verde J., Peisach C., Lee Mazzarella, Lelio 2006 STAMPA http://hdl.handle.net/11588/307848 eng eng ispartofbook:XXII Congresso Nazionale della Società Chimica Italiana XXII Congresso Nazionale della Società Chimica Italiana firstpage:257 lastpage:257 http://hdl.handle.net/11588/307848 info:eu-repo/semantics/conferencePaper 2006 ftunivnapoliiris 2024-06-03T14:30:30Z Antarctic fish hemoglobins (AFHbs) exhibit a peculiar oxidation process. Indeed, upon oxidation, these tetrameric proteins show a remarkable propensity to evolve toward the formation of a bis-hystidine complex, hemichrome, [1,2]. The crystal structures of the oxidized AFHbs, isolated from Trematomus newnesi and Trematomus bernacchii, have shown that a) a chains go to aquo-met, whereas the b chains to hemichrome, and b) the quaternary structure is intermediate between the physiological R and T states [3]. The EPR analysis of the ferric AFHbs at physiological pH reveals two distinct hemichromes (I, II) in solution. The crystal structure (1.5 Å) of the oxidized form (hemichrome I) of the AFHbs isolated from T. bernacchii, HbTb, attributes the difference between the two EPR-distinct hemichromes to the deviation from the ideal hexa-coordination. The reactivity of the two HbTb hemichromes with CN- (studied via EPR, and confirmed via X-ray crystallography) is very different. In fact, only hemichrome I reacts in stechiometric conditions, converting into the cyano-met and a penta-coordinated ferric form. Interestingly, ferric AFHbs reveal a low peroxidasic activity with respect to mammalian and temperate fish hemoglobins. [1] Riccio A., et al. Proc. Natl. Acad. Sci. US, 2002, 99, 9801; [2] Vitagliano L., et al. Eur. .J. Biochem, 2004, 271, 1651. [3] Mazzarella L., et al. Proteins in press. Conference Object Antarc* Antarctic IRIS Università degli Studi di Napoli Federico II Antarctic |
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Open Polar |
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IRIS Università degli Studi di Napoli Federico II |
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ftunivnapoliiris |
language |
English |
description |
Antarctic fish hemoglobins (AFHbs) exhibit a peculiar oxidation process. Indeed, upon oxidation, these tetrameric proteins show a remarkable propensity to evolve toward the formation of a bis-hystidine complex, hemichrome, [1,2]. The crystal structures of the oxidized AFHbs, isolated from Trematomus newnesi and Trematomus bernacchii, have shown that a) a chains go to aquo-met, whereas the b chains to hemichrome, and b) the quaternary structure is intermediate between the physiological R and T states [3]. The EPR analysis of the ferric AFHbs at physiological pH reveals two distinct hemichromes (I, II) in solution. The crystal structure (1.5 Å) of the oxidized form (hemichrome I) of the AFHbs isolated from T. bernacchii, HbTb, attributes the difference between the two EPR-distinct hemichromes to the deviation from the ideal hexa-coordination. The reactivity of the two HbTb hemichromes with CN- (studied via EPR, and confirmed via X-ray crystallography) is very different. In fact, only hemichrome I reacts in stechiometric conditions, converting into the cyano-met and a penta-coordinated ferric form. Interestingly, ferric AFHbs reveal a low peroxidasic activity with respect to mammalian and temperate fish hemoglobins. [1] Riccio A., et al. Proc. Natl. Acad. Sci. US, 2002, 99, 9801; [2] Vitagliano L., et al. Eur. .J. Biochem, 2004, 271, 1651. [3] Mazzarella L., et al. Proteins in press. |
author2 |
Vergara, Alessandro Merlino, Antonello Franzese, Marisa G., Di Prisco C., Verde J., Peisach C., Lee Mazzarella, Lelio |
format |
Conference Object |
author |
VERGARA, ALESSANDRO MERLINO, ANTONELLO FRANZESE, MARISA MAZZARELLA, LELIO G. Di Prisco C. Verde J. Peisach C. Lee |
spellingShingle |
VERGARA, ALESSANDRO MERLINO, ANTONELLO FRANZESE, MARISA MAZZARELLA, LELIO G. Di Prisco C. Verde J. Peisach C. Lee A combined EPR and X-ray crystallography approach to the reactivity of hemichromes |
author_facet |
VERGARA, ALESSANDRO MERLINO, ANTONELLO FRANZESE, MARISA MAZZARELLA, LELIO G. Di Prisco C. Verde J. Peisach C. Lee |
author_sort |
VERGARA, ALESSANDRO |
title |
A combined EPR and X-ray crystallography approach to the reactivity of hemichromes |
title_short |
A combined EPR and X-ray crystallography approach to the reactivity of hemichromes |
title_full |
A combined EPR and X-ray crystallography approach to the reactivity of hemichromes |
title_fullStr |
A combined EPR and X-ray crystallography approach to the reactivity of hemichromes |
title_full_unstemmed |
A combined EPR and X-ray crystallography approach to the reactivity of hemichromes |
title_sort |
combined epr and x-ray crystallography approach to the reactivity of hemichromes |
publishDate |
2006 |
url |
http://hdl.handle.net/11588/307848 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
ispartofbook:XXII Congresso Nazionale della Società Chimica Italiana XXII Congresso Nazionale della Società Chimica Italiana firstpage:257 lastpage:257 http://hdl.handle.net/11588/307848 |
_version_ |
1802646346808688640 |