title: Purification of recombinant G protein alpha subunits from Escherichia coli.
abstract: The purification of recombinant G protein a subunits expressed in Escherichia coli (E. coli) is a convenient and inexpensive method to obtain homogeneous preparations of protein for biochemical and biophysical analyses. Wild-type and mutant forms of G alpha are easily produced for analysis of their intrinsic biochemical properties, as well as for reconstitution with receptors, effectors, regulators, and G protein beta gamma subunits. Methods are described for the expression of Gi alpha and Gs alpha proteins in E. coli. Protocols are provided for the purification of untagged G protein a subunits using conventional chromatography and histidine (His)-tagged subunits using metal chelate chromatography. Modification of G alpha with myristate can be recapitulated in E. coli by expressing N-myristoyltransferase (NMT) with its G protein substrate. Protocols for the production and purification of myristoylated G alpha are presented.
mesh_terms: D002846:Chromatography, Affinity / Q000379:methods*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000302:isolation & purification* / Q000378:metabolism; D044385:GTP-Binding Protein alpha Subunits / Q000302:isolation & purification* / Q000378:metabolism; D011994:Recombinant Proteins / Q000302:isolation & purification* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029968:Escherichia coli Proteins; D044385:GTP-Binding Protein alpha Subunits; D011994:Recombinant Proteins