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Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Protein dynamics in cytochrome P450 molecular recognition and substrate specificity using 2D IR vibrational echo
Megan C Thielges1, Jean K Chung, Michael D Fayer
1Department of Chemistry, Stanford University, Stanford, California 94305, United States.
Journal of the American Chemical Society
|February 26, 2011
Summary
Protein dynamics influence cytochrome P450 substrate specificity. Studies show substrate binding alters enzyme dynamics, affecting hydroxylation activity and molecular recognition in cytochrome P450cam.
Area of Science:
- Biochemistry
- Enzymology
- Spectroscopy
Background:
- Cytochrome P450 enzymes are crucial for drug metabolism and biological processes.
- Understanding substrate specificity is key to their function.
- Protein dynamics are increasingly recognized as a factor in enzyme activity.
Purpose of the Study:
- To investigate the role of protein dynamics in substrate recognition and hydroxylation specificity of cytochrome P450cam.
- To elucidate how molecular motions contribute to the enzyme's activity on diverse substrates.
Main Methods:
- Utilized 2D IR vibrational echo spectroscopy to measure fast time-scale dynamics.
- Employed carbon monoxide (CO) as a vibrational probe at the active site.
- Studied substrate-free and substrate-bound states of cytochrome P450cam with various substrates.
Main Results:
- Identified three populated conformational states in substrate-free cytochrome P450cam with slow dynamics.
- Observed that substrate binding stabilizes a specific conformational state, leading to faster dynamics.
- Correlated observed dynamics with substrate hydroxylation specificity, binding affinity, and molecular volume.
Conclusions:
- Picosecond time-scale motions are critical for variations in cytochrome P450cam activity across different substrates.
- Protein dynamics play a significant role in the molecular recognition and specificity of cytochrome P450 enzymes.
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