Purification of GTP-binding proteins from bovine brain membranes. Identification of heterogeneity of the alpha-subunit of Go proteins.
Using high-resolution Mono Q column chromatography, we purified 6 distinct peaks of GTP-binding proteins from bovine brain membranes. Five of them consisted of 3 polypeptides with alpha beta gamma-subunits and served as the substrate of islet-activating protein (IAP), pertussis toxin. The other one was purified as alpha-subunit alone and was also ADP-ribosylated by IAP in the presence of beta gamma-subunits. When each alpha-subunit was characterized by immunoblot analysis using various antibodies with defined specificity, the two of them were identified as Gi-1 and Gi-2, and other 4 appeared to be Go or Go-like G proteins. The alpha-subunits of immunologically Go-like proteins were apparently distinguishable from one another on elution profiles from the Mono Q column. Thus, there was a heterogeneity of the alpha-subunit of Go in the brain membranes.
Kobayashi
I
I
Department of Life Science, Faculty of Science, Tokyo Institute of Technology, Yokohama, Japan.
Shibasaki
H
H
Takahashi
K
K
Kikkawa
S
S
Ui
M
M
Katada
T
T
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D019204:GTP-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000378:metabolism; D015151:Immunoblotting; D046911:Macromolecular Substances; D009243:NAD / Q000378:metabolism; D013873:Thionucleotides / Q000378:metabolism
D046911:Macromolecular Substances; D013873:Thionucleotides; D009243:NAD; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins