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A New Type of Exo-Beta-Glucuronidase Acting Only on Non-Sulfated Glycosaminoglycans

T Nakamura, K Takagaki, M Majima, S Kimura, K Kubo, M Endoss

J Biol Chem. 1990 Apr 5;265(10):5390-7.

PMID: 2108135

Abstract:

Using chondroitin as a substrate, a new type of exo-beta-glucuronidase (EC 3.2.1.31) from rabbit liver was purified using a combination of ammonium sulfate fractionation, DEAE-cellulose chromatography, gel filtration on Sephracryl S-300, affinity chromatography through heparin-Sepharose CL-6B, and preparative polyacrylamide gel electrophoresis. This enzyme acts only on non-sulfated glycosaminoglycans and their oligosaccharides and was shown to be quite different from exo-beta-glucuronidase, which does act on p-nitro-phenyl-beta-D-glucuronide with regard to the following properties. 1) Neither sulfated glycosaminoglycanoligosaccharides nor p-nitrophenyl-beta-D-glucuronide were substrates for the enzyme. 2) The molecular weight was found to be about 130,000 by gel filtration, compared with a molecular weight of 280,000-300,000 for beta-glucuronidase, which acts on p-nitro-phenyl-beta-D-glucuronide. 3) The enzyme showed maximal activity at pH 5.0, compared with an optimum pH of 4.5 for beta-glucuronidase, which acts on p-nitro-phenyl-beta-D-glucuronide. 4) The enzyme showed maximal activity in 0.075 M NaCl but no activity above 0.25 M NaCl. 5) The enzyme was inhibited strongly by compounds bearing a sulfate group. 6) The enzyme did not react with an antibody against beta-glucuronidase acting on p-nitrophenyl-D-glucuronide. It is suggested that the enzyme may be involved in the catabolism of glycosaminoglycans, acting especially on chondroitin after the desulfation reaction and/or hyaluronic acid, but showing little involvement with the detoxification system.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP17685051 Phenyl-β-D-glucuronide Phenyl-β-D-glucuronide 17685-05-1 Price
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