Skip to main content
Journal cover image

Subtype-specific binding of azidoanilido-GTP by purified G protein alpha subunits.

Publication ,  Journal Article
Fields, TA; Linder, ME; Casey, PJ
Published in: Biochemistry
June 7, 1994

Azidoanilido-GTP (AA-GTP), a hydrolysis-resistant, photoreactive GTP analog, is becoming an increasingly popular tool for identifying activation of specific G proteins by receptors within native plasma membranes. Despite the use of AA-GTP as an affinity probe, surprisingly little is known regarding the ability of various G protein alpha subunits to bind this analog. To directly address this issue, we compared the ability of four purified G protein alpha subunits (Go, Gi2, Gs, and Gz) to bind AA-GTP with their ability to bind GTP gamma S, a GTP analog commonly used to characterize the GTP-binding properties of G proteins. All four G alpha subunits tested bound AA-GTP in a manner distinct from their binding of GTP gamma S. One of these proteins, Gs alpha, required millimolar levels of free Mg2+ for significant binding of AA-GTP, while Go alpha and Gi alpha 2 displayed peak AA-GTP binding at approximately 100 microM free Mg2+. The fourth G alpha subunit, Gz, bound AA-GTP very poorly relative to GTP gamma S regardless of the magnesium concentration. These results indicate that individual G protein alpha subunits differ markedly in their ability to bind AA-GTP. Use of AA-GTP to identify specific G protein-receptor interactions must therefore take into account the varied abilities of G alpha subunits to bind this analog.

Duke Scholars

Published In

Biochemistry

DOI

ISSN

0006-2960

Publication Date

June 7, 1994

Volume

33

Issue

22

Start / End Page

6877 / 6883

Location

United States

Related Subject Headings

  • Recombinant Proteins
  • Protein Binding
  • Photochemistry
  • Peptide Fragments
  • Magnesium
  • In Vitro Techniques
  • Guanosine Triphosphate
  • GTP-Binding Proteins
  • Cattle
  • Biochemistry & Molecular Biology
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Fields, T. A., Linder, M. E., & Casey, P. J. (1994). Subtype-specific binding of azidoanilido-GTP by purified G protein alpha subunits. Biochemistry, 33(22), 6877–6883. https://doi.org/10.1021/bi00188a017
Fields, T. A., M. E. Linder, and P. J. Casey. “Subtype-specific binding of azidoanilido-GTP by purified G protein alpha subunits.Biochemistry 33, no. 22 (June 7, 1994): 6877–83. https://doi.org/10.1021/bi00188a017.
Fields TA, Linder ME, Casey PJ. Subtype-specific binding of azidoanilido-GTP by purified G protein alpha subunits. Biochemistry. 1994 Jun 7;33(22):6877–83.
Fields, T. A., et al. “Subtype-specific binding of azidoanilido-GTP by purified G protein alpha subunits.Biochemistry, vol. 33, no. 22, June 1994, pp. 6877–83. Pubmed, doi:10.1021/bi00188a017.
Fields TA, Linder ME, Casey PJ. Subtype-specific binding of azidoanilido-GTP by purified G protein alpha subunits. Biochemistry. 1994 Jun 7;33(22):6877–6883.
Journal cover image

Published In

Biochemistry

DOI

ISSN

0006-2960

Publication Date

June 7, 1994

Volume

33

Issue

22

Start / End Page

6877 / 6883

Location

United States

Related Subject Headings

  • Recombinant Proteins
  • Protein Binding
  • Photochemistry
  • Peptide Fragments
  • Magnesium
  • In Vitro Techniques
  • Guanosine Triphosphate
  • GTP-Binding Proteins
  • Cattle
  • Biochemistry & Molecular Biology