title: Using light scattering to determine the stoichiometry of protein complexes.
abstract: The stoichiometry of a protein complex can be calculated from an accurate measurement of the complex's molecular weight. Multiangle laser light scattering in combination with size exclusion chromatography and interferometric refractometry provides a powerful means for determining the molecular weights of proteins and protein complexes. In contrast to conventional size exclusion chromatography and analytical centrifugation, measurements do not rely on the use of molecular weight standards and are not affected by the shape of the proteins. The technique is based on the direct relationship between the amount of light scattered by a protein in solution, and the product of its concentration and molecular weight. A typical experimental configuration includes a size exclusion column to fractionate the sample, a light scattering detector to measure scattered light, and an interferometric refractometer to measure protein concentration. The determination of the molecular weight of an anthrax toxin complex will be used to illustrate how multiangle laser light scattering can be used to determine the stoichiometry of protein complexes.
authors: Department of Laboratory Medicine and Pathobiology, University of Toronto, Medical Sciences Building, Room 6308, 1 King's College Circle, Toronto, ON, Canada, M5S 1A8, jeremy.mogridge@utoronto.ca.
authors: Jeremy
authors: J
authors: Mogridge
mesh_terms: D002850:Chromatography, Gel; D000067493:Dynamic Light Scattering; D007368:Interferometry; D008970:Molecular Weight; D046912:Multiprotein Complexes / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012031:Refractometry; D012996:Solutions / Q000737:chemistry
chemical_list: D046912:Multiprotein Complexes; D011506:Proteins; D012996:Solutions