Biomaterial Database

Purification and properties of two isoenzymes of beta-N-acetylhexosaminidase from Turbo cornutus. 1979

K K Yeung, and A J Owen, and J A Dain

Department of Biochemistry and Biophysics, University of Rhode Island, Kingston 02881.

1. beta-N-acetylhexosaminidase isoenzymes from the gastropod, T. cornutus, were purified and their properties studied. 2. The two isoenzymes, designated A and B were separated by DEAE-Sephadex column chromatography and further purified by CM-cellulose, Concanavalin-A-Sepharose-4B and Sephadex G-200 column chromatography. 3. beta-N-Acetylhexosaminidase A and B were purified 416 and 208 fold, with yields of 10.6 and 5.1%, respectively. 4. The two isoenzymes appear homogeneous on polyacrylamide gel electrophoresis, with the A form migrating faster towards the anode than the B form. 5. The purified isoenzymes are virtually free of all other common glycosidase contaminations. 6. The apparent molecular weight of both beta-N-acetylhexosaminidase A and B is about 100,000 when estimated with gel filtration column chromatography and the pH optimum for both is 4.0. 7. Both beta-N-acetylhexosaminidase isoenzyme activities are stimulated by Cl-, Br-, F-, I- and NO3-, and inhibited by Hg+, Ag+, Fe3+, N-acetylglucosamine and N-acetylgalactosamine. 8. The Km values of beta-N-acetylhexosaminidase A and B for the substrate p-nitrophenyl-beta-2-acetamide-2-deoxy-D-glucopyranoside were 2.9 and 3.2 mM, respectively.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008974	Mollusca	A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.	Molluscs,Mollusks,Mollusc,Molluscas,Mollusk
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001619	beta-N-Acetylhexosaminidases	A hexosaminidase specific for non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. It acts on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES. Two specific mammalian isoenzymes of beta-N-acetylhexoaminidase are referred to as HEXOSAMINIDASE A and HEXOSAMINIDASE B. Deficiency of the type A isoenzyme causes TAY-SACHS DISEASE, while deficiency of both A and B isozymes causes SANDHOFF DISEASE. The enzyme has also been used as a tumor marker to distinguish between malignant and benign disease.	beta-N-Acetylhexosaminidase,N-Acetyl-beta-D-hexosaminidase,beta-Hexosaminidase,beta-N-Acetyl-D-hexosaminidase,beta-N-Acetyl-hexosaminidase,N Acetyl beta D hexosaminidase,beta Hexosaminidase,beta N Acetyl D hexosaminidase,beta N Acetyl hexosaminidase,beta N Acetylhexosaminidase,beta N Acetylhexosaminidases
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities