Related Experiment Video
Updated: Aug 14, 2026

Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
Homodimerization of soluble guanylyl cyclase subunits. Dimerization analysis using a glutathione s-transferase
1Department of Pharmacology and Toxicology, Julius-Maximilians-University, D-97078 Wuerzburg, Germany.
Abstract:
Soluble guanylyl cyclase (sGC) is an alpha/beta-heterodimeric hemoprotein that, upon interaction with the intercellular messenger molecule NO, generates cGMP. Although the related family of particulate guanylyl cyclases (pGCs) forms active homodimeric complexes, it is not known whether homodimerization of sGC subunits occurs. We report here the expression in Sf9 cells of glutathione S-transferase-tagged recombinant human sGCalpha1 and beta1 subunits, applying a novel and rapid purification method based on GSH-Sepharose affinity chromatography. Surprisingly, in intact Sf9 cells, both homodimeric GSTalpha/alpha and GSTbeta/beta complexes were formed that were catalytically inactive. Upon coexpression of the respective complementary subunits, GSTalpha/beta or GSTbeta/alpha heterodimers were preferentially formed, whereas homodimers were still detectable. When subunits were mixed after expression, e.g. GSTbeta and beta or GSTalpha and beta, no dimerization was observed. In conclusion, our data suggest the previously unrecognized possibility of a physiological equilibrium between homo- and heterodimeric sGC complexes.
More Related Videos
12:43Genetic and Biochemical Approaches for In Vivo and In Vitro Assessment of Protein Oligomerization: The Ryanodine Receptor Case Study
Published on: July 27, 2016
13:51Detection of Small GTPase Prenylation and GTP Binding Using Membrane Fractionation and GTPase-linked Immunosorbent Assay
Published on: November 11, 2018
Related Concept Videos
GTPases and their Regulation
Large G-proteins, also known...
Activation and Inactivation of G Proteins