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1. 1. α- l -Fucosidase from hamster and six inbred mouse strains contains two to three unique basic isoelectric forms (above pI 7.0) in addition to the usual acidic and neutral isoforms from pI 4–7. Rat liver α- l -Fucosidase contains multiple isoforms between pI values of 4.0 and 7.3 whereas guinea pig liver α- l -Fucosidase exhibits a single, broad isoform at pI 5.3. 2. 2. All the α- l -fucosidases have similar KM values (0.05–0.12 mM) for 4-methylumbelliferyl-α- l -fucopyranoside, but pH-activity curves which are significantly different in optima and per cent of optimal activity in the acid region. 3. 3. Double-antibody immunoprecipitation experiments indicate that rodent liver α- l -fucosidase cross react to varying extents with polyclonal antibody against human liver α- l -fucosidase. 4. 4. Hamster, guinea pig and mouse liver α- l -fucosidase exhibit significantly less binding than human and rat liver fucosidases to the agarose-E-aminocaproylfucosamine affinity resin.

1. 1. The α- l -fucosidase from the marine mollusc Littorina littorea L. was purified approximately 225-fold; the purified enzyme was free of other glycosidase activities and showed a major band by polyacrylamide gel electrophoresis. 2. 2. Only one form of α- l -fucosidase has been detected by isoelectric focusing at pH 5.4 ± 0.1. 3. 3. The enzyme has an optimum pH of 6.5, Km of 3.0 × 10−4 M and Vmax of 2.6 μmol/mg per min with p-nitrophenyl α- l -fucopyranoside as substrate. 4. 4. l -fucose was a competitive inhibitor and Hg2+ was a no competitive inhibitor for α- l -fucosidase activity. 5. 5. This enzyme is stable in the range of pH values 4.0–9.0. Molecular weight of α- l -fucosidase by gel filtration was about 220,000. 6. 6. The carbohydrate composition of the enzyme was determined. The purified enzyme contains: glucose, 7.4%; galactose, 2.2%; mannose, 1.8%; and hexosamine, 2.2%.

1. 1. Seven renal glycohydrolases were measured in four subcellular fractions prepared from highly inbred aglycosuric (AV-line) and glycosuric (XA-line) Chinese hamsters. 2. 2. α- d -galactosidase and β- d -galactosidase were highest in the nuclear (N) and supernatant (S) fractions; both fractions showed reduced activities in the XA animals. 3. 3. α- d -mannosidase was chiefly a particulate enzyme and its decrease in XA animals was evident in N, lysosomal-mitochondrial (LM) and mitochondrial-microsomal (MM) fractions. 4. 4. No significant difference in N- acetyl -β- d - glucosaminidase was found in any of these subcellular fractions between AV and XA animals. 5. 5. Although total α- l -fucosidase and β- d -fucosidase levels were similar in AV and XA kidneys, a difference was observed in the S fraction. 6. 6. β- d -glucuronidase was virtually absent in N and LM fractions and the S fraction of AV kidneys showed higher activity than the XAs.

1. 1. The contents of hexoses and hexosamines in brain, liver, and kidney of streptozotocin diabetic mice are significantly increased in comparison to the controls. These differences for hexoses contents in the heart are not significant. 2. 2. N- acetyl-β- d -glucosaminidase and β- d -glucosidase activities in brain, liver and kidney of diabetic mice are significantly higher when compared to the controls. 3. 3. However, β- d -galactosidase activity is significantly lower in brain, liver, spleen and kidney of the diabetic mice, in comparison to the controls and similar in heart. 4. 4. α- d -Mannosidase activity of diabetic mice is significantly increased in spleen and heart and significantly decreased in liver and kidney. 5. 5. α- l -Fucosidase of diabetic mice shows higher activities, with significant differences, in liver and spleen; however, in heart and kidney the activities are significantly lower. 6. 6. Brain sialyltransferase and galactosyltransferase activities are significantly increased in diabetic mice; but for heart and kidney these differences are not significant. 7. 7. The activity for brain and kidney fucosyltransferase is not significant and that for the other assayed organs is significantly higher in comparison to the controls.

1. 1. β-N-Acetylglucosaminidase was partially purified from the digestive gland of the three coastal New England bivalves Mercenaria mercenaria Spisula solidissuma and Mya arenaria and their properties compared. 2. 2. Heat inactivation studies on the β-N-acetylglucosaminidases preincubated at 45°C revealed that the preparation from S. solidissima was stable up to 60 min, while thatfrom M. arenaria and M. mercenaria lost 47 and 91% of their original activities under these conditions, respectively. 3. 3. Inhibition studies indicated that d -glucoronolactone is more inhibitory iswards the M. arenaria enzyme, while HgCI2 appears to be less inhibitory towards the S. solidissima enzyme. 4. 4. The Vmax value for β-N-acetylglucosaminidase from M. mercenaria was approximately 2.5 fold greater than that from S. solidissima and M. arenaria 5. 5. Other characteristics of the β-N-acetylglucosaminidases such as pH optimum Km, mol. wt, energy of activation, and effect of ionic strengtt on enzyme activity were found to be aimilar for all three species. 6. 6. The digestive gland of all three species of clams also contained the following activities: β- d - galactosidase, α- d -galactosidase, α- l -fucosidase, α-N-acetylgalactosaminidase and α- d -mannosidase. Trace amounts of β- d -xylosidase, α- d -xylosidase, α- d -glucosidase and β- d -glucuronidase were also detected.

1. 1. A β- d -glucosidase was purified from Thaumetopoea pityocampa larvae (Lepidoptera Thaumetopoeidae). 2. 2. It was found to be homogenous on electrofocusing and on electrophoresis. 3. 3. The enzyme has a pI of 3.60 and an optimum pH of 6.0. 4. 4. The Km for p- nitrophenyl-β- d -glucoside is 0.39 mM. The enzyme has a broad specificity; it also hydrolyzes the p-nitrophenyl derivatives of β- d -galactose, β- d -fucose, and to a lower extent, of β- d -xylose. From the kinetic parameters we concluded that this enzyme is a β- d -glucosidase/β- d -fucosidase with a secondary β- d -galactosidase activity. 5. 5. The enzyme hydrolyzes sophorose and laminaribiose (Km = 4.2 mM) and a series of natural β- d -glucosides (Kmforconiferin = 1.49 mM). 6. 6. Methyl-β- d -glucoside, gentiobiose, cellobiose and lactose are faintly or not at all hydrolyzed.

1. 1. Two types of β- d -galactosidase activity are present in sheep organs. 2. 2. A β- d -galactosidase that binds to concanavalin A and has an acidic pH-optimum, characteristic of a lysosomal hydrolase, predominates in sheep brain, kidney and spleen. 3. 3. A different β- d -galactosidase that does not bind to concanavalin A is also present in these tissues and accounts for 95% of the β- d -galactosidase in sheep liver. 4. 4. β- d -Glucosidase, β- d -fucosidase, β- d -xylosidase and α- l -arabinosidase activities also do not bind to concanavalin A. 5. 5. All five activities that do not bind to concanavalin A show the same pH-dependence, thermal stability and inhibition by Cl− ions and 2,5-dihydroxymethyl-3,4-dihydroxypyrrolidine (DMDP), a specific β- d -glucosidase inhibitor. 6. 6. It is postulated that a broad specificity glycosidase which has greatest activity towards β- d -glucosides accounts for all these activities. 7. 7. As the true β- d -galactosidase is not inhibited by DMDP it will be possible to use this inhibitor in a differential assay for the two types of β- d -galactosidase in sheep with a deficiency of the lysosomal β- d -galactosidase.

1. 1. Two forms of α- l -fucosidase were isolated from the gastropod, Turbo cornutus and their properties studied. 2. 2. Fucosidase I (pI 6.78) and Fucosidase II (pI 5.5) were purified by a scheme which included Sephadex G-200 column chromatography, DEAE-Sephadex column chromatography, heat treatment, CM-cellulose column chromatography and preparative isoelectric focusing. 3. 3. The purified forms were substantially free of all other glycosidase contaminations and had specific activity approximately 73 and 65 fold of the starting material. 4. 4. The pH activity profile of Fucosidase I displayed a pH optimum at 4.0, and that of Fucosidase II showed a broad optimum centered at pH 3.6. 5. 5. Fucosidase I was thermolabile and lost greater than 90% of its activity when incubated at 55°C for 15 min. Fucosidase II was thermostable, and lost less than 30% of its initial activity under identical incubation conditions. 6. 6. Both enzymes had an apparent molecular weight of 230,000 ± 20,000 and were inhibited by Hg2+, l -fucose and l -galactose. 7. 7. The Km values of Fucosidase I and II for the substrate p- nitrophenyl-α- l -fucopyranoside were 0.38 and 0.14 mM, respectively.

1. 1. The enzyme studied shows β- d -fucosidase, β- d -glucosidase and β- d -galactosidase activities, always associated in a single peak in all the chromatographic steps. 2. 2. The enzyme shows, at low and high substrate concentrations, two different K m and V max , suggesting a substrate-activation model; the highest V max /K m values are for β- d -fucosidase activity. 3. 3. β- d -Fucosides and β- d -glucosides completely compete for a common active site in mixed-substrates experiments, while β- d -galactosides only partially compete with both glycosides. With d -fucose, glucose and galactose as inhibitors, the enzyme shows, at low substrate concentrations, coincident K i values for β- d -fucosidase and β- d -glucosidase activities, different from those for β- d -galactosidase activity. With those inhibitors, the enzyme shows a partial competitive-type inhibition. 4. 4. All the kinetic evidences suggest that this enzyme has two different active sites. 5. 5. At high substrate concentrations some activities are activated by d -fucose, glucose and galactose, probably in relation with a transglycosylation mechanism.

1. 1. Crude liver α- l -fucosidase was investigated in 10 vertebrate species ranging from fish to human using 4-methylumbelliferyl-α- l -fucopyranoside as substrate. 2. 2. The α- l -fucosidases were characterized by determinations of pH optima and isoelectric focusing profiles, K m values, thermostabilities after preincubation at 45°C and 60°C, and immunoprecipitation by anti-human liver α- l -fucosidase antibody. 3. 3. Results suggest differences in liver α- l -fucosidases with respect to pH optima, thermostabilities and isoelectric focusing profiles. However, the K m values were largely similar and 9 to 10 species were precipitated by the human IgG preparation, suggesting antigenic similarity.

1. 1. A number of different glycosidase activities were found in abalone ( Haliotus rufescens ) hepatopancreas extracts. 2. 2. Using p- nitrophenyl derivatives, the following glycosidase activities were found: α- l -fucosidase (36) β- d -galactosidase (30·3), α- d -mannosidase (27·2), β- d -glucuronidase (25), N-acetyl-β- d -glucosaminidase (11·4), α- d -galactosidase (8), β- d -glucosidase (8), β- d -xylulosidase (2·9) and α- d -glucosidase (1·67). 3. 3. A number of natural substrates were also tested.