title: Determination of the partial specific volume of cytochrome P-450 as a model of a membrane protein.
abstract: Cytochrome P-450 has been used as a representative of membrane proteins in investigations for experimental determination of its partial specific volume. Diverse methods were employed: sucrose density gradient centrifugation, sedimentation velocity measurements in media of varying density, as well as sedimentation equilibrium studies in H2O and D2O. The results are compared with each other and with the theoretically calculated value. As a reason for discrepancies preferential solvation is discussed, and recommendations are given for the methodical approach to determine the partial specific volume and, hence, the molecular weight of a membrane protein.
mesh_terms: D000818:Animals; D002499:Centrifugation, Density Gradient / Q000379:methods; D003577:Cytochrome P-450 Enzyme System; D003903:Deuterium; D017666:Deuterium Oxide; D008433:Mathematics; D008565:Membrane Proteins; D008862:Microsomes, Liver / Q000378:metabolism; D008954:Models, Biological; D008970:Molecular Weight; D011487:Protein Conformation; D011817:Rabbits; D014867:Water
chemical_list: D008565:Membrane Proteins; D014867:Water; D003577:Cytochrome P-450 Enzyme System; D003903:Deuterium; D017666:Deuterium Oxide