title: P-450 binding to substrates camphor and linalool versus pressure.
abstract: The spin equilibrium of two bacterial cytochrome P-450 enzymes are compared by their visible spectra versus temperature and pressure. P-450 from Pseudomonas linalool shows a much weaker dependence on pressure than P-450 from P. putida which has camphor as substrate. The linalool system denatures at a higher pressure (3 kbar) than the camphor system (1 kbar) and shows a weaker dependence on external solvent conditions. The camphor system shows evidence of the binding of a second substrate molecule which reverses the effect of the first on the spin equilibrium. A model involving two substrate molecules is an alternative explanation of the apparent saturation with camphor of the spin equilibrium.
mesh_terms: D000080462:Acyclic Monoterpenes; D002164:Camphor / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005290:Ferric Compounds; D006874:Hydrostatic Pressure; D039821:Monoterpenes; D011189:Potassium Chloride / Q000494:pharmacology; D011549:Pseudomonas / Q000201:enzymology*; D012997:Solvents; D013045:Species Specificity; D013379:Substrate Specificity; D013729:Terpenes / Q000378:metabolism*; D013816:Thermodynamics; D014867:Water
chemical_list: D000080462:Acyclic Monoterpenes; D005290:Ferric Compounds; D039821:Monoterpenes; D012997:Solvents; D013729:Terpenes; D014867:Water; D011189:Potassium Chloride; D002164:Camphor; D003577:Cytochrome P-450 Enzyme System; C018584:linalool