Cryogenic stabilization of myoglobin photoproducts

M. Sassaroli, S. Dasgupta, Denis L. Rousseau

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

The low frequency resonance Raman spectra of photodissociated carbon monoxymyoglobin at cryogenic temperatures (4-77 K) differ from those of deoxymyoglobin. Intensity differences occur in several low frequency porphyrin modes, and intensity and frequency differences occur in the iron-histidine stretching mode. This mode appears at about 225 cm-1 in deoxymyoglobin. At the lowest temperature studied, ~4 K, the frequency of the iron-histine stretching mode in the photoproduct is ~223 cm-1, and the intensity is very low. When the temperature of the photoproduct is increased, the intensity of the mode increases, but its frequency is unchanged. The differences between the photoproduct and the deoxy preparation persist to 77 K, the highest temperature studied, and are independent of whether samples are frozen in phosphate buffer or a 50:50 ethylene glycol/phosphate buffer mixture. It is proposed that the frequency of the iron-histidine stretching mode is governed by the tilt angle of the histidine with respect to the normal to the heme plane, and the intensity of the mode is governed by the overlap between the δ* orbital of the iron-histidine bond and the π* orbital of the porphyrin macrocycle. This model can account for differences between the resonance Raman spectra for the photoproduct and the deoxy preparations of both hemoglobin and myoglobin. Furthermore, by considering the F-helix motions in going from 6-coordinate to 5-coordinate hemoglobin and myoglobin, the heme relaxation of these proteins at room temperature with 10-ns pulses can be explained. Based on the findings reported here, low temperature relaxation pathways for both hemoglobin and myoglobin are proposed.

Original languageEnglish (US)
Pages (from-to)13704-13713
Number of pages10
JournalJournal of Biological Chemistry
Volume261
Issue number29
StatePublished - 1986
Externally publishedYes

Fingerprint

Myoglobin
Cryogenics
Stabilization
Histidine
Temperature
Iron
Stretching
Hemoglobins
Porphyrins
Heme
Raman scattering
Buffers
Phosphates
Ethylene Glycol
Carbon
Proteins

ASJC Scopus subject areas

  • Biochemistry

Cite this

Cryogenic stabilization of myoglobin photoproducts. / Sassaroli, M.; Dasgupta, S.; Rousseau, Denis L.

In: Journal of Biological Chemistry, Vol. 261, No. 29, 1986, p. 13704-13713.

Research output: Contribution to journalArticle

Sassaroli, M, Dasgupta, S & Rousseau, DL 1986, 'Cryogenic stabilization of myoglobin photoproducts', Journal of Biological Chemistry, vol. 261, no. 29, pp. 13704-13713.
Sassaroli, M. ; Dasgupta, S. ; Rousseau, Denis L. / Cryogenic stabilization of myoglobin photoproducts. In: Journal of Biological Chemistry. 1986 ; Vol. 261, No. 29. pp. 13704-13713.
@article{0e922ca257244fff945cff9b303cf6bc,
title = "Cryogenic stabilization of myoglobin photoproducts",
abstract = "The low frequency resonance Raman spectra of photodissociated carbon monoxymyoglobin at cryogenic temperatures (4-77 K) differ from those of deoxymyoglobin. Intensity differences occur in several low frequency porphyrin modes, and intensity and frequency differences occur in the iron-histidine stretching mode. This mode appears at about 225 cm-1 in deoxymyoglobin. At the lowest temperature studied, ~4 K, the frequency of the iron-histine stretching mode in the photoproduct is ~223 cm-1, and the intensity is very low. When the temperature of the photoproduct is increased, the intensity of the mode increases, but its frequency is unchanged. The differences between the photoproduct and the deoxy preparation persist to 77 K, the highest temperature studied, and are independent of whether samples are frozen in phosphate buffer or a 50:50 ethylene glycol/phosphate buffer mixture. It is proposed that the frequency of the iron-histidine stretching mode is governed by the tilt angle of the histidine with respect to the normal to the heme plane, and the intensity of the mode is governed by the overlap between the δ* orbital of the iron-histidine bond and the π* orbital of the porphyrin macrocycle. This model can account for differences between the resonance Raman spectra for the photoproduct and the deoxy preparations of both hemoglobin and myoglobin. Furthermore, by considering the F-helix motions in going from 6-coordinate to 5-coordinate hemoglobin and myoglobin, the heme relaxation of these proteins at room temperature with 10-ns pulses can be explained. Based on the findings reported here, low temperature relaxation pathways for both hemoglobin and myoglobin are proposed.",
author = "M. Sassaroli and S. Dasgupta and Rousseau, {Denis L.}",
year = "1986",
language = "English (US)",
volume = "261",
pages = "13704--13713",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "29",

}

TY - JOUR

T1 - Cryogenic stabilization of myoglobin photoproducts

AU - Sassaroli, M.

AU - Dasgupta, S.

AU - Rousseau, Denis L.

PY - 1986

Y1 - 1986

N2 - The low frequency resonance Raman spectra of photodissociated carbon monoxymyoglobin at cryogenic temperatures (4-77 K) differ from those of deoxymyoglobin. Intensity differences occur in several low frequency porphyrin modes, and intensity and frequency differences occur in the iron-histidine stretching mode. This mode appears at about 225 cm-1 in deoxymyoglobin. At the lowest temperature studied, ~4 K, the frequency of the iron-histine stretching mode in the photoproduct is ~223 cm-1, and the intensity is very low. When the temperature of the photoproduct is increased, the intensity of the mode increases, but its frequency is unchanged. The differences between the photoproduct and the deoxy preparation persist to 77 K, the highest temperature studied, and are independent of whether samples are frozen in phosphate buffer or a 50:50 ethylene glycol/phosphate buffer mixture. It is proposed that the frequency of the iron-histidine stretching mode is governed by the tilt angle of the histidine with respect to the normal to the heme plane, and the intensity of the mode is governed by the overlap between the δ* orbital of the iron-histidine bond and the π* orbital of the porphyrin macrocycle. This model can account for differences between the resonance Raman spectra for the photoproduct and the deoxy preparations of both hemoglobin and myoglobin. Furthermore, by considering the F-helix motions in going from 6-coordinate to 5-coordinate hemoglobin and myoglobin, the heme relaxation of these proteins at room temperature with 10-ns pulses can be explained. Based on the findings reported here, low temperature relaxation pathways for both hemoglobin and myoglobin are proposed.

AB - The low frequency resonance Raman spectra of photodissociated carbon monoxymyoglobin at cryogenic temperatures (4-77 K) differ from those of deoxymyoglobin. Intensity differences occur in several low frequency porphyrin modes, and intensity and frequency differences occur in the iron-histidine stretching mode. This mode appears at about 225 cm-1 in deoxymyoglobin. At the lowest temperature studied, ~4 K, the frequency of the iron-histine stretching mode in the photoproduct is ~223 cm-1, and the intensity is very low. When the temperature of the photoproduct is increased, the intensity of the mode increases, but its frequency is unchanged. The differences between the photoproduct and the deoxy preparation persist to 77 K, the highest temperature studied, and are independent of whether samples are frozen in phosphate buffer or a 50:50 ethylene glycol/phosphate buffer mixture. It is proposed that the frequency of the iron-histidine stretching mode is governed by the tilt angle of the histidine with respect to the normal to the heme plane, and the intensity of the mode is governed by the overlap between the δ* orbital of the iron-histidine bond and the π* orbital of the porphyrin macrocycle. This model can account for differences between the resonance Raman spectra for the photoproduct and the deoxy preparations of both hemoglobin and myoglobin. Furthermore, by considering the F-helix motions in going from 6-coordinate to 5-coordinate hemoglobin and myoglobin, the heme relaxation of these proteins at room temperature with 10-ns pulses can be explained. Based on the findings reported here, low temperature relaxation pathways for both hemoglobin and myoglobin are proposed.

UR - http://www.scopus.com/inward/record.url?scp=0023025916&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023025916&partnerID=8YFLogxK

M3 - Article

C2 - 3759989

AN - SCOPUS:0023025916

VL - 261

SP - 13704

EP - 13713

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 29

ER -