Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins
Antarctic fish hemoglobins (AF-Hbs) exhibit an unusual auto-oxidation process. Our previous crystallographic and spectroscopic investigations have demonstrated that, upon oxidation, these tetrameric proteins show a remarkable propensity to evolve towards the formation of low-spin bis-histidine compl...
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ftunivnapoliiris:oai:www.iris.unina.it:11588/307834 2024-06-23T07:47:34+00:00 Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins 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/11588/307834 eng eng ispartofbook:XIVth International Conference on Dioxygen binding and sensing proteins XIVth International Conference on Dioxygen binding and sensing proteins firstpage:75 lastpage:75 http://hdl.handle.net/11588/307834 info:eu-repo/semantics/conferencePaper 2006 ftunivnapoliiris 2024-06-10T14:58:46Z Antarctic fish hemoglobins (AF-Hbs) exhibit an unusual auto-oxidation process. Our previous crystallographic and spectroscopic investigations have demonstrated that, upon oxidation, these tetrameric proteins show a remarkable propensity to evolve towards the formation of low-spin bis-histidine complexes, hemichromes, even under physiological conditions [1,2]. The crystal structures of the fully oxidized forms of Trematomus newnesi and Trematomus bernacchii AF-Hbs have shown that α and β chains follow different oxidation pathways. Indeed, α chains form aquo-met, whereas β chains form hemichromes. Interestingly, the quaternary structures of these ferric forms are intermediate [1,2] between the physiological R and T hemoglobin states [3]. Frozen solution EPR spectra of the ferric AF-Hbs at physiological pH reveal two distinct hemichrome signals (I, II), corresponding to two bis-histidine structures with different tilt angles, one of which (I) is consistent with the high resolution crystal structure (1.5 Å) of the oxidized form of T. bernacchii AF-Hb, HbTb. EPR studies show that one of the hemichromes (I) preferentially reacts with CN ̄. With excess CN ̄, a cyano-met and a rhombic high spin signal were resolved. These signals may correlate with the high resolution crystal structure of the ferric form of HbTb after cyanidation (1.4 Å), which exhibits two different β heme structures, attributed to a cyano-met and a penta-coordinated form. A possible functional role of hemichromes in Antarctic fish is discussed in terms of protection from oxidative stress [4].[1] Riccio A., Vitagliano L., Zagari A., di Prisco G., Mazzarella L. Proc. Natl. Acad. Sci. US, 2002, 99, 9801; [2] Vitagliano L., Bonomi G., Riccio A., di Prisco G., Smulevich G., Mazzarella L. Eur. .J. Biochem, 2004, 271, 1651. [3] Mazzarella L., Vergara A., Vitagliano L., Merlino A., Bonomi G., Scala S., Verde C., di Prisco G. Proteins, Str. Funct. Bioinf. in press. [4] Feng L., Zhou S., Gu L., Gell D.A., Mackay J. P., Weiss M.J., Gow A.J., Shi Y., Nature ... Conference Object Antarc* Antarctic IRIS Università degli Studi di Napoli Federico II Antarctic Mackay ENVELOPE(168.517,168.517,-77.700,-77.700) Gow ENVELOPE(162.667,162.667,-71.333,-71.333) |
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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 (AF-Hbs) exhibit an unusual auto-oxidation process. Our previous crystallographic and spectroscopic investigations have demonstrated that, upon oxidation, these tetrameric proteins show a remarkable propensity to evolve towards the formation of low-spin bis-histidine complexes, hemichromes, even under physiological conditions [1,2]. The crystal structures of the fully oxidized forms of Trematomus newnesi and Trematomus bernacchii AF-Hbs have shown that α and β chains follow different oxidation pathways. Indeed, α chains form aquo-met, whereas β chains form hemichromes. Interestingly, the quaternary structures of these ferric forms are intermediate [1,2] between the physiological R and T hemoglobin states [3]. Frozen solution EPR spectra of the ferric AF-Hbs at physiological pH reveal two distinct hemichrome signals (I, II), corresponding to two bis-histidine structures with different tilt angles, one of which (I) is consistent with the high resolution crystal structure (1.5 Å) of the oxidized form of T. bernacchii AF-Hb, HbTb. EPR studies show that one of the hemichromes (I) preferentially reacts with CN ̄. With excess CN ̄, a cyano-met and a rhombic high spin signal were resolved. These signals may correlate with the high resolution crystal structure of the ferric form of HbTb after cyanidation (1.4 Å), which exhibits two different β heme structures, attributed to a cyano-met and a penta-coordinated form. A possible functional role of hemichromes in Antarctic fish is discussed in terms of protection from oxidative stress [4].[1] Riccio A., Vitagliano L., Zagari A., di Prisco G., Mazzarella L. Proc. Natl. Acad. Sci. US, 2002, 99, 9801; [2] Vitagliano L., Bonomi G., Riccio A., di Prisco G., Smulevich G., Mazzarella L. Eur. .J. Biochem, 2004, 271, 1651. [3] Mazzarella L., Vergara A., Vitagliano L., Merlino A., Bonomi G., Scala S., Verde C., di Prisco G. Proteins, Str. Funct. Bioinf. in press. [4] Feng L., Zhou S., Gu L., Gell D.A., Mackay J. P., Weiss M.J., Gow A.J., Shi Y., Nature ... |
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 Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins |
author_facet |
VERGARA, ALESSANDRO MERLINO, ANTONELLO FRANZESE, MARISA MAZZARELLA, LELIO G. Di Prisco C. Verde J. Peisach C. Lee |
author_sort |
VERGARA, ALESSANDRO |
title |
Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins |
title_short |
Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins |
title_full |
Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins |
title_fullStr |
Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins |
title_full_unstemmed |
Stereochemistry, formation and reactivity of hemichromes in Antarctic fish hemoglobins |
title_sort |
stereochemistry, formation and reactivity of hemichromes in antarctic fish hemoglobins |
publishDate |
2006 |
url |
http://hdl.handle.net/11588/307834 |
long_lat |
ENVELOPE(168.517,168.517,-77.700,-77.700) ENVELOPE(162.667,162.667,-71.333,-71.333) |
geographic |
Antarctic Mackay Gow |
geographic_facet |
Antarctic Mackay Gow |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
ispartofbook:XIVth International Conference on Dioxygen binding and sensing proteins XIVth International Conference on Dioxygen binding and sensing proteins firstpage:75 lastpage:75 http://hdl.handle.net/11588/307834 |
_version_ |
1802651699280609280 |