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Measurement of the GTPase Activity of Signal-Transducing G-Proteins in Neuronal Membranes

  • Marva Sweeney
Part of the Methods in Molecular Biology™ book series (MIMB, volume 41)

Abstract

The methods described in this chapter are designed to measure the hydrolysis of guanosine triphosphate (GTP) to inorganic phosphate (Pi) and guanosine diphosphate (GDP), a reaction catalyzed by the GTPase enzymes (EC 3.6.1.-). The theory behind the experimental design involves using [γ-32P]GTP as a marker, whereby any GTPase-induced hydrolysis will result in the 32P label appearing as 32P, and as unhydrolyzed [γ-32P]GTP. It was originally described by Cassel and Selinger (1). 32P, must be separated from [γ-32P]GTP, and then can be easily quantitated by using a liquid scintillation counter. The amount of 32Pi is directly proportional to the amount of [γ-32P]GTP hydrolyzed, and, therefore, proportional to the activity of GTPases in the preparation.

Keywords

GTPase Activity Guanosine Triphosphate Guanosine Diphosphate Trypsin Inhibitor Unit Nonhydrolyzable Analog 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Humana Press Inc , Totowa, NJ 1995

Authors and Affiliations

  • Marva Sweeney
    • 1
  1. 1.Department of Physiology, College of MedicineUniversity of SaskatchewanSaskatoonCanada

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