Separation and properties of β-N-acetylglucosaminidases A, B and I from horse brain

Reglero, Ángel; Esteban, M.B.; Cabezas, JoséA.

doi:10.1016/0020-711x(81)90104-x

Cited by 7 publications

(2 citation statements)

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“…The enzyme from the octopus has other features in common with the b-N-acetylhexosaminidases A and B : the native enzymes have similar apparent M , values [8,26,30]; the PI has been shown to be a tetramer made up of two different subunits (Fig. 5 ) and evidence from several laboratories also supports the multi-subunit nature of the native mammalian enzymes [28,31 -331.…”

Section: Discussionmentioning

confidence: 96%

“…While in the octopus PI represented about 80% of the total activity, in mammalian tissues p-N-acetylglucosaminidase A, possibly corresponding to [W, was the most prominent species [I, 8, 24,25,27-291. The octopus PI has the following features in common with the P-N-acetylhexosaminidase B : (a) both are not retained by DEAE-cellulose at pH 7.0 but are adsorbed on hydroxyapatite [I, 25,261; (b) both have an alkaline isoelectric point [30]; (c) PI was more heat-stable than PIV (unpublished results), as B appears less heat-sensitive than A [8,27].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Purification and Characterization of a β‐N‐Acetylglucosaminidase from Octopus vulgaris

Ceccarini

D’Aniello

Cacace³

et al. 1983

European Journal of Biochemistry

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We have purified a p-N-acetylglucosaniinidase from the hepatopancreas of the octopus which we have called PI. The enzyme was homogeneous as judged by Sephadex column chromatography, isoelectric focusing, non-denaturing gel electrophoresis at two different pH and with sodium dodecyl sulphate/polyacrylamide gel electrophoresis. The native protcin has an apparent molecular weight of 120000 and we can conclude that it is a tetramer made up of two CI and two P subunits with apparent M , of 27000 and 34000, respectively. Using N M R spectroscopy we have examined the specificity of fi1 and have established that the enzyme hydrolyses the p1,4 linkage of N-acetylglucosamine but at only a specific site of the substrates used, two glycopeptides isolated from ovalbumin. To our knowledge this is the first known exoglycosidase which has both linkage and site specificity. P-N-Acetylglucosaminidase (EC 3.2.1.30) has been studied and purified from a variety of sources [1 -81. The enzyme is an exoglycosidase capable of removing N-acetylglucosamine from oligosaccharides and glycopeptides or glycoproteins. All of the hexosaminidases so far studied do not appear to recognize specific glycone substrates of known structure; however, they require the p configuration of the sugar. In a survey for specific glycosidases initiated by one of us (C.C.), the hepatopancreas of octopus was screened for glycosidasc activities [9]. This organ was found to be an extremely rich source of hexosaminidase activity and in this paper we report the purification and the biochemical properties of a p-Nacetylglucosaminidase. We also demonstrate that this enzyme is specific for the Pl,4 linkage of N-acetylglucosamine situated at a unique site of ovalbumin glycopeptide A [lo, 111. We have established this by high-resolution 'H-NMR spectroscopy. To our knowledge this exquisite specificity has never been previously reported for an exoglycosidase and suggests that glycosidase activity can be as finely regulated as is the biosynthesis of oligosaccharide fine structure.

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Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 99%