High pressure, a tool for exploring heme protein active sites

Gaston Hui Bon Hoa, Mark A. McLean, Stephen G. Sligar

Research output: Contribution to journalReview articlepeer-review


High pressure is an interesting and suitable parameter in the study of the dynamics and stability of proteins. The effects of pressure on proteins delineates its volumic (ΔV°) and energetic (ΔG°) parameters. An enormous amount of effort has been invested by several laboratories in developing basic theory and high pressure techniques that allow the determination of barotropic parameters. Cytochrome P450s, one of the largest super families of heme proteins, are good models for high pressure studies. Two distinct pressure-induced spin transitions of the heme iron in the active site and a P450 to P420 inactivation process have been characterized. The obtained reaction volumes of these two processes for a series of analog-bound cytochrome P450s are compared. We have shown that both the spin volume and the inactivation volume are dependent on the substrate analogs which are known to modulate the polarity and hydration of the heme pocket. Several linear correlations were found between these reaction volumes and the physico-chemical properties of the heme protein such as the polarity-induced exposure of tyrosines, the hydration of the cytochrome CYP101 heme pocket, and the mobility and binding of the substrates indicate that they constitute the main contribution to the complex thermodynamic reaction volume parameters. This interpretation allows us to conclude that cytochrome CYP101, CYP2B4 and CYP102 possess a similar mechanism of substrate binding. Interestingly the barotropic behaviors of monomeric cytochrome P450s are quite different from those of oligomeric and hetorooligomeric cytochrome P450s. The interactions of heterooligomeric subunits influence the stability of individual cytochrome P450s and the asymmetric organization of subunits which can control and modulate the activity and the recognition with NADPH-cytochrome P450 reductase.

Original languageEnglish (US)
Pages (from-to)297-308
Number of pages12
JournalBiochimica et Biophysica Acta - Protein Structure and Molecular Enzymology
Issue number1-2
StatePublished - Mar 25 2002


  • Active site hydration
  • High pressure effect
  • Oligomerization dynamics
  • P450 dynamics
  • Pressure-induced P420
  • Stability of P450

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'High pressure, a tool for exploring heme protein active sites'. Together they form a unique fingerprint.

Cite this