Glucosidase emulsin

His work on enzymes was continued during the Bonn period. Studies on acid phosphatases were carried out that made a major contribution to our knowledge of these enzymes. " The isolation of a crystalline /3-glucosidase from the emulsin of sweet almonds may be regarded as the crowning achievement of his work on glycosidases. ... 

Glucosidase and 0-galactosidase (sweet almond emulsin)[36] Glutamine synthetase (native octameric brain) 371 Glycogen phosphorylase At3 ]... 

The effect on /3-glucosidase activity of substitution in the glucon has been carefully investigated by the school of Helferich. It has been established that substitution of the hydroxyl groups at C2, C3 and C4 renders the /3-D-glucopyranoside unhydrolyzable (i.e., E.V. less than 10 s) by almond emulsin. This refers to phenyl 3-methyl-/3-D-gluco-pyranoside,29 phenyl 2,4,6-trimethyl-/3-D-glucopyranoside89 and to the... 

Emil Fischer developed a strong interest in the structural requirements for enzyme activity as the result of effects of changes in the structures of the a-and -methyl glucosides on their properties as substrates for the enzymes invertin and emulsin, which, as we have seen, he had shown to be a- and yS-glucosidases, respectively. As already mentioned, he was fascinated in 1895 by the fact that emulsin had no effect on either the a- or /2-methyl xylosides (33). In a 1912 publication with Karl Zach (34), he reported that -methyl 6-deoxyglucoside was hydrolyzed by emulsin and wrote ... 

D. E. Walker and B. Axelrod, Evidence for a single catalytic site on the P-d-glucosidase-P-D-galactosidase of almond emulsin, Arch. Biochem. Biophys., 187 (1978) 102-107. 

Results are expressed as fig of p-nitrophenol liberated per g of seed from 6 mM p-nitrophenyl a-D-mannoside in 1 hr at 37° and pH 5. Coarsely ground beans. Defatted sweet-almond meal. A commercial /3-D-glucosidase preparation purified from emulsin. a-D-Mannosidase activity is given per g of purified material. 

The first evidence for the presence of an a-D-mannosyl link in ovalbumin glycopeptides was provided by the action of almond emulsin,101,102 although the absence of /3-D-mannosidase from the enzyme preparation was not confirmed until later.103 The presence of 2-acetamido-2-deoxy-/M>glucosidase in emulsin left doubt as to the terminal position of all of the D-mannose released. 

Electrophoresis, of starch, I, 251 Emicymarin, I, 148, 156 Emulsin. See also j9-Glucosidase. Emulsins, V, 60-66... 

It is uncertain whether the -D-galactosidase and the n-glucosidase of sweet almond emulsin are the same or different enzymes. See B. Helferich, Ergtlb. Emymforsch., 7, 83 (1938). 

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