Glucuronidase, Beta

I.U.B.: 3.2.1.31
β-D-Glucuronoside glucuronosohydrolase

Enzymatic Reaction (image will open in a new window) 

β-Glucuronidase hydrolyzes conjugated glucuronides.

It is ubiquitious in animal lysozymes.

The enzyme has found wide application in determining urinary steroids.

Characteristics of β-glucuronidase from Bovine Liver:

Molecular weight:

290,000 (Himeno et al. 1974).

Composition:

It is a sialic acid containing glycoprotein. The amino acid and carbohydrate content have been reported by Himeno et al. (1974). It is probable that the heterogeneity reported by Plapp and Cole (1967) is due to differing carbohydrate content. Wang and Touster (1972) report on an active center study using the rat liver enzyme which may be similar to that from beef liver.

Optimum pH:

4.4 (Wang and Touster 1972).

Extinction coefficient:

= 17.0 (Plapp and Cole 1966).

Isoelectric point:

5.1 (Himeno et al. 1974).

Specificity:

The enzyme hydrolyzes a large variety of conjugated glucuronides but not α- or β-glucosides. See report by Tomasic and Keglevic (1973).

Inhibitors:

It is strongly, reversibly inhibited by various organic peroxides (Christner et al. 1970).

Stability:

Lyophilized, Worthington glucuronidase is stable 6 - 12 months at 2 - 8°C.