title: Quantifying the activation of the small molecular weight G-protein ras.
abstract: Low molecular weight guanine-nucleotide binding proteins are molecular switches involved in a wide range of cellular functions in eukaryotes. Ras is activated when a membrane receptor is bound by a ligand and the GDP bound to the Ras protein is exchanged for GTP. Once GTP is bound, the Ras three-dimensional conformation changes and binds the kinase Raf. This protein-protein interaction can be used to "pull-down" activated Ras from a cell lysate. The amount of activated Ras is quantitated through immunoblotting and densitometry. This procedure is excellent as a multiweek investigational laboratory.
authors.affiliation: Chemistry Department, Lawrence University, Appleton, Wisconsin 54912.
authors.forename: Katharine
authors.initials: K
authors.lastname: Chapman
authors.forename: David J
authors.initials: DJ
authors.lastname: Hall