Glucose-6-phosphatase (G6Pase, EC 3.1.3.9) is widely present in animals, plants, microorganisms, and cells. It is the rate-limiting enzyme in gluconeogenesis that hydrolyzes glucose-6-phosphate to produce glucose, playing an important role in maintaining blood glucose homeostasis.
Determination Principle: G6Pase catalyzes the conversion of glucose-6-phosphate to glucose. Mutarotase and glucose dehydrogenase subsequently catalyze the reduction of NAD⁺ to NADH. The activity of G6Pase is determined by measuring the rate of NADH production at 340 nm.