Assay of glutaminase activity by colorimetric determination of glutamate

✍ Scribed by F. Javier Gella; M. Angeles Pascual

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 305 KB
• Volume: 127
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(82)90180-4

✦ Synopsis

An assay method for glutaminase is described in which the rate of release of glutamate from glutamine is followed in a second step by means of two coupled reactions involving glutamate dehydrogenase and the phenazine methosulfate-catalyzed reduction of iodonitrotetrazolium chloride by NADH. The assay is rapid, sensitive, and reproducible, and may be employed to determine glutaminase activity in crude as well as in purified enzyme preparations.

Methods

Reagents. Triethanolamine, phenazine methosulfate, and ammonium chloride were obtained from Merck, Darmstadt, GFR; ADP, glutamine, and NAD+ were from