Optical and IR absorption as probe of dynamics of heme proteins

Solomon S. Stavrov, Wayne W. Wright, Jane M. Vanderkooi, J. Fidy, A. Kaposi

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The spectroscopy of horseradish peroxidase with and without the substrate analogue benzohydroxamic acid (BHA) was monitored in different solvents as a function of the temperature in the interval from 10 to 300 K. Thermal broadening of the Q(0,0) optical absorption band arises mainly from interaction of the electronic π → π transition with the heme vibrations. In contrast, the width of the IR absorption band of CO bound to heme is controlled by the coupling of the CO transition moment to the electric field of the protein matrix. The IR bandwidth of the substrate free enzyme in the glycerol/H2O solvent hardly changes in the glassy matrix and strongly increases upon heating above the glass transition. Heating of the same enzyme in the trehalose/ H2O glass considerably broadens the band. The binding of the substrate strongly diminishes the temperature broadening of the CO band. This result is consistent with the view that the BHA strongly reduces the amplitude of vibrations of the heme pocket environment. Unusually strong thermal broadening of the CO band above the glass transition is interpreted to be caused by thermal population of a very flexible excited conformational substate. The thermal broadening of the same band in the trehalose glass is caused by an increase of the protein vibrational amplitude in each of the conformational substates, their population being independent of the temperature in the glassy matrix.

Original languageEnglish
Pages (from-to)255-258
Number of pages4
JournalBiopolymers - Peptide Science Section
Volume67
Issue number4-5
DOIs
Publication statusPublished - 2002

Fingerprint

Hemeproteins
Carbon Monoxide
Glass
Hot Temperature
Heme
Trehalose
Vibration
Heating
Temperature
Absorption spectra
Glass transition
Substrates
Enzymes
Proteins
Acids
Horseradish Peroxidase
Glycerol
Light absorption
Population
Spectrum Analysis

Keywords

  • Dynamics
  • Heme proteins
  • IR absorption
  • Optical absorption

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biophysics

Cite this

Optical and IR absorption as probe of dynamics of heme proteins. / Stavrov, Solomon S.; Wright, Wayne W.; Vanderkooi, Jane M.; Fidy, J.; Kaposi, A.

In: Biopolymers - Peptide Science Section, Vol. 67, No. 4-5, 2002, p. 255-258.

Research output: Contribution to journalArticle

Stavrov, Solomon S. ; Wright, Wayne W. ; Vanderkooi, Jane M. ; Fidy, J. ; Kaposi, A. / Optical and IR absorption as probe of dynamics of heme proteins. In: Biopolymers - Peptide Science Section. 2002 ; Vol. 67, No. 4-5. pp. 255-258.
@article{db5ecd49f0ac48e59f3ccb340393012c,
title = "Optical and IR absorption as probe of dynamics of heme proteins",
abstract = "The spectroscopy of horseradish peroxidase with and without the substrate analogue benzohydroxamic acid (BHA) was monitored in different solvents as a function of the temperature in the interval from 10 to 300 K. Thermal broadening of the Q(0,0) optical absorption band arises mainly from interaction of the electronic π → π transition with the heme vibrations. In contrast, the width of the IR absorption band of CO bound to heme is controlled by the coupling of the CO transition moment to the electric field of the protein matrix. The IR bandwidth of the substrate free enzyme in the glycerol/H2O solvent hardly changes in the glassy matrix and strongly increases upon heating above the glass transition. Heating of the same enzyme in the trehalose/ H2O glass considerably broadens the band. The binding of the substrate strongly diminishes the temperature broadening of the CO band. This result is consistent with the view that the BHA strongly reduces the amplitude of vibrations of the heme pocket environment. Unusually strong thermal broadening of the CO band above the glass transition is interpreted to be caused by thermal population of a very flexible excited conformational substate. The thermal broadening of the same band in the trehalose glass is caused by an increase of the protein vibrational amplitude in each of the conformational substates, their population being independent of the temperature in the glassy matrix.",
keywords = "Dynamics, Heme proteins, IR absorption, Optical absorption",
author = "Stavrov, {Solomon S.} and Wright, {Wayne W.} and Vanderkooi, {Jane M.} and J. Fidy and A. Kaposi",
year = "2002",
doi = "10.1002/bip.10103",
language = "English",
volume = "67",
pages = "255--258",
journal = "Biopolymers",
issn = "0006-3525",
publisher = "John Wiley and Sons Inc.",
number = "4-5",

}

TY - JOUR

T1 - Optical and IR absorption as probe of dynamics of heme proteins

AU - Stavrov, Solomon S.

AU - Wright, Wayne W.

AU - Vanderkooi, Jane M.

AU - Fidy, J.

AU - Kaposi, A.

PY - 2002

Y1 - 2002

N2 - The spectroscopy of horseradish peroxidase with and without the substrate analogue benzohydroxamic acid (BHA) was monitored in different solvents as a function of the temperature in the interval from 10 to 300 K. Thermal broadening of the Q(0,0) optical absorption band arises mainly from interaction of the electronic π → π transition with the heme vibrations. In contrast, the width of the IR absorption band of CO bound to heme is controlled by the coupling of the CO transition moment to the electric field of the protein matrix. The IR bandwidth of the substrate free enzyme in the glycerol/H2O solvent hardly changes in the glassy matrix and strongly increases upon heating above the glass transition. Heating of the same enzyme in the trehalose/ H2O glass considerably broadens the band. The binding of the substrate strongly diminishes the temperature broadening of the CO band. This result is consistent with the view that the BHA strongly reduces the amplitude of vibrations of the heme pocket environment. Unusually strong thermal broadening of the CO band above the glass transition is interpreted to be caused by thermal population of a very flexible excited conformational substate. The thermal broadening of the same band in the trehalose glass is caused by an increase of the protein vibrational amplitude in each of the conformational substates, their population being independent of the temperature in the glassy matrix.

AB - The spectroscopy of horseradish peroxidase with and without the substrate analogue benzohydroxamic acid (BHA) was monitored in different solvents as a function of the temperature in the interval from 10 to 300 K. Thermal broadening of the Q(0,0) optical absorption band arises mainly from interaction of the electronic π → π transition with the heme vibrations. In contrast, the width of the IR absorption band of CO bound to heme is controlled by the coupling of the CO transition moment to the electric field of the protein matrix. The IR bandwidth of the substrate free enzyme in the glycerol/H2O solvent hardly changes in the glassy matrix and strongly increases upon heating above the glass transition. Heating of the same enzyme in the trehalose/ H2O glass considerably broadens the band. The binding of the substrate strongly diminishes the temperature broadening of the CO band. This result is consistent with the view that the BHA strongly reduces the amplitude of vibrations of the heme pocket environment. Unusually strong thermal broadening of the CO band above the glass transition is interpreted to be caused by thermal population of a very flexible excited conformational substate. The thermal broadening of the same band in the trehalose glass is caused by an increase of the protein vibrational amplitude in each of the conformational substates, their population being independent of the temperature in the glassy matrix.

KW - Dynamics

KW - Heme proteins

KW - IR absorption

KW - Optical absorption

UR - http://www.scopus.com/inward/record.url?scp=0036289070&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036289070&partnerID=8YFLogxK

U2 - 10.1002/bip.10103

DO - 10.1002/bip.10103

M3 - Article

C2 - 12012441

AN - SCOPUS:0036289070

VL - 67

SP - 255

EP - 258

JO - Biopolymers

JF - Biopolymers

SN - 0006-3525

IS - 4-5

ER -