Chlamydomonas chloroplast ferrous hemoglobin: Heme pocket structure and reactions with ligands

Manon Couture, Tapan Kanti Das, H. Caroline Lee, Jack Peisach, Denis L. Rousseau, Beatrice A. Wittenberg, Jonathan B. Wittenberg, Michel Guertin

Research output: Contribution to journalArticle

107 Citations (Scopus)

Abstract

We report the optical and resonance Raman spectral characterization of ferrous recombinant Chlamydomonas LI637 hemoglobin. We show that it is present in three pH-dependent equilibrium forms including a 4-coordinate species at acid pH, a 5-coordinate high spin species at neutral pH, and a 6- coordinate low spin species at alkaline pH. The proximal ligand to the heme is the imidazole group of a histidine. Kinetics of the reactions with ligands were determined by stopped-flow spectroscopy. At alkaline pH, combination with oxygen, nitric oxide, and carbon monoxide displays a kinetic behavior that is interpreted as being rate-limited by conversion of the 6-coordinate form to a reactive 5-coordinate form. At neutral pH, combination rates of the 5-coordinate form with oxygen and carbon monoxide were much faster (>107 μM-1 s-1). The dissociation rate constant measured for oxygen is among the slowest known, 0.014 s-1, and is independent of pH. Replacement of the tyrosine 63 (B10) by leucine or of the putative distal glutamine by glycine increases the dissociation rate constant 70- and 30-fold and increases the rate of autoxidation 20- and 90-fold, respectively. These results are consistent with at least two hydrogen bonds stabilizing the bound oxygen molecule, one from tyrosine B10 and the other from the distal glutamine. In addition, the high frequency (232 cm-1) of the iron-histidine bond suggests a structure that lacks any proximal strain thus contributing to high ligand affinity.

Original languageEnglish (US)
Pages (from-to)6898-6910
Number of pages13
JournalJournal of Biological Chemistry
Volume274
Issue number11
DOIs
StatePublished - Mar 12 1999

Fingerprint

Chlamydomonas
Chloroplasts
Heme
Hemoglobins
Oxygen
Ligands
Carbon Monoxide
Glutamine
Histidine
Tyrosine
Rate constants
Kinetics
Leucine
Glycine
Hydrogen bonds
Nitric Oxide
Iron
Spectroscopy
Molecules
Acids

ASJC Scopus subject areas

  • Biochemistry

Cite this

Chlamydomonas chloroplast ferrous hemoglobin : Heme pocket structure and reactions with ligands. / Couture, Manon; Das, Tapan Kanti; Lee, H. Caroline; Peisach, Jack; Rousseau, Denis L.; Wittenberg, Beatrice A.; Wittenberg, Jonathan B.; Guertin, Michel.

In: Journal of Biological Chemistry, Vol. 274, No. 11, 12.03.1999, p. 6898-6910.

Research output: Contribution to journalArticle

Couture, M, Das, TK, Lee, HC, Peisach, J, Rousseau, DL, Wittenberg, BA, Wittenberg, JB & Guertin, M 1999, 'Chlamydomonas chloroplast ferrous hemoglobin: Heme pocket structure and reactions with ligands', Journal of Biological Chemistry, vol. 274, no. 11, pp. 6898-6910. https://doi.org/10.1074/jbc.274.11.6898
Couture, Manon ; Das, Tapan Kanti ; Lee, H. Caroline ; Peisach, Jack ; Rousseau, Denis L. ; Wittenberg, Beatrice A. ; Wittenberg, Jonathan B. ; Guertin, Michel. / Chlamydomonas chloroplast ferrous hemoglobin : Heme pocket structure and reactions with ligands. In: Journal of Biological Chemistry. 1999 ; Vol. 274, No. 11. pp. 6898-6910.
@article{6ed78f26c7c044c0ab045d916d29f7df,
title = "Chlamydomonas chloroplast ferrous hemoglobin: Heme pocket structure and reactions with ligands",
abstract = "We report the optical and resonance Raman spectral characterization of ferrous recombinant Chlamydomonas LI637 hemoglobin. We show that it is present in three pH-dependent equilibrium forms including a 4-coordinate species at acid pH, a 5-coordinate high spin species at neutral pH, and a 6- coordinate low spin species at alkaline pH. The proximal ligand to the heme is the imidazole group of a histidine. Kinetics of the reactions with ligands were determined by stopped-flow spectroscopy. At alkaline pH, combination with oxygen, nitric oxide, and carbon monoxide displays a kinetic behavior that is interpreted as being rate-limited by conversion of the 6-coordinate form to a reactive 5-coordinate form. At neutral pH, combination rates of the 5-coordinate form with oxygen and carbon monoxide were much faster (>107 μM-1 s-1). The dissociation rate constant measured for oxygen is among the slowest known, 0.014 s-1, and is independent of pH. Replacement of the tyrosine 63 (B10) by leucine or of the putative distal glutamine by glycine increases the dissociation rate constant 70- and 30-fold and increases the rate of autoxidation 20- and 90-fold, respectively. These results are consistent with at least two hydrogen bonds stabilizing the bound oxygen molecule, one from tyrosine B10 and the other from the distal glutamine. In addition, the high frequency (232 cm-1) of the iron-histidine bond suggests a structure that lacks any proximal strain thus contributing to high ligand affinity.",
author = "Manon Couture and Das, {Tapan Kanti} and Lee, {H. Caroline} and Jack Peisach and Rousseau, {Denis L.} and Wittenberg, {Beatrice A.} and Wittenberg, {Jonathan B.} and Michel Guertin",
year = "1999",
month = "3",
day = "12",
doi = "10.1074/jbc.274.11.6898",
language = "English (US)",
volume = "274",
pages = "6898--6910",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "11",

}

TY - JOUR

T1 - Chlamydomonas chloroplast ferrous hemoglobin

T2 - Heme pocket structure and reactions with ligands

AU - Couture, Manon

AU - Das, Tapan Kanti

AU - Lee, H. Caroline

AU - Peisach, Jack

AU - Rousseau, Denis L.

AU - Wittenberg, Beatrice A.

AU - Wittenberg, Jonathan B.

AU - Guertin, Michel

PY - 1999/3/12

Y1 - 1999/3/12

N2 - We report the optical and resonance Raman spectral characterization of ferrous recombinant Chlamydomonas LI637 hemoglobin. We show that it is present in three pH-dependent equilibrium forms including a 4-coordinate species at acid pH, a 5-coordinate high spin species at neutral pH, and a 6- coordinate low spin species at alkaline pH. The proximal ligand to the heme is the imidazole group of a histidine. Kinetics of the reactions with ligands were determined by stopped-flow spectroscopy. At alkaline pH, combination with oxygen, nitric oxide, and carbon monoxide displays a kinetic behavior that is interpreted as being rate-limited by conversion of the 6-coordinate form to a reactive 5-coordinate form. At neutral pH, combination rates of the 5-coordinate form with oxygen and carbon monoxide were much faster (>107 μM-1 s-1). The dissociation rate constant measured for oxygen is among the slowest known, 0.014 s-1, and is independent of pH. Replacement of the tyrosine 63 (B10) by leucine or of the putative distal glutamine by glycine increases the dissociation rate constant 70- and 30-fold and increases the rate of autoxidation 20- and 90-fold, respectively. These results are consistent with at least two hydrogen bonds stabilizing the bound oxygen molecule, one from tyrosine B10 and the other from the distal glutamine. In addition, the high frequency (232 cm-1) of the iron-histidine bond suggests a structure that lacks any proximal strain thus contributing to high ligand affinity.

AB - We report the optical and resonance Raman spectral characterization of ferrous recombinant Chlamydomonas LI637 hemoglobin. We show that it is present in three pH-dependent equilibrium forms including a 4-coordinate species at acid pH, a 5-coordinate high spin species at neutral pH, and a 6- coordinate low spin species at alkaline pH. The proximal ligand to the heme is the imidazole group of a histidine. Kinetics of the reactions with ligands were determined by stopped-flow spectroscopy. At alkaline pH, combination with oxygen, nitric oxide, and carbon monoxide displays a kinetic behavior that is interpreted as being rate-limited by conversion of the 6-coordinate form to a reactive 5-coordinate form. At neutral pH, combination rates of the 5-coordinate form with oxygen and carbon monoxide were much faster (>107 μM-1 s-1). The dissociation rate constant measured for oxygen is among the slowest known, 0.014 s-1, and is independent of pH. Replacement of the tyrosine 63 (B10) by leucine or of the putative distal glutamine by glycine increases the dissociation rate constant 70- and 30-fold and increases the rate of autoxidation 20- and 90-fold, respectively. These results are consistent with at least two hydrogen bonds stabilizing the bound oxygen molecule, one from tyrosine B10 and the other from the distal glutamine. In addition, the high frequency (232 cm-1) of the iron-histidine bond suggests a structure that lacks any proximal strain thus contributing to high ligand affinity.

UR - http://www.scopus.com/inward/record.url?scp=0033548681&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033548681&partnerID=8YFLogxK

U2 - 10.1074/jbc.274.11.6898

DO - 10.1074/jbc.274.11.6898

M3 - Article

C2 - 10066743

AN - SCOPUS:0033548681

VL - 274

SP - 6898

EP - 6910

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 11

ER -