Related Experiment Video
Updated: Jul 29, 2026

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
A study of the horseradish peroxidase catalytic site by FTIR spectroscopy
1School of Biology, University of St. Andrews, St. Andrews KY16 9ST, UK. wji@st-andrews.ac.uk
Abstract:
Vibrational changes in the catalytic site of horseradish peroxidase were investigated by FTIR (Fourier-transform infrared) spectroscopy in the 1000-2500 cm(-1) range. Difference spectra were generated by photolysis of the haemII-CO compound at different pH/pD values. The spectra report on the fine structure around the catalytic site and show vibrational changes of protein backbone, amino acid residues and cofactors. Assignments of the FTIR vibrations can be made based upon known crystal structures, comparisons with absorption frequencies and extinction coefficients of model amino acids and cofactors, effects of H2O/2H2O exchange and changes of pH/pD. Concomitant with the photolysis of the CO ligand are changes due to haem and protein vibrations, predominant among which are arginine and histidine residue vibrations.
Related Concept Videos
UV–Vis Spectroscopy: Woodward–Fieser Rules
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to the...
IR Frequency Region: Fingerprint Region
The...
Applications of IR Spectroscopy: Overview
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
