ISSN:
1572-9699
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract An inducible cell-surface-bound starch-degrading enzyme produced byCorynebacterium diphtheriae typegravis in tryptose-sodium chloride-maltose broth was partially purified by diethylaminoethylcellulose (DEAE) column chromatography. The partially purified enzyme had approximately six times the specific activity of the crude enzyme. Forty-five percent of the enzyme was recovered in the partially purified form after DEAE chromatography. A molecular weight for the enzyme of approximately 61 200 was obtained by glycerol density gradient centrifugation. The enzyme was inhibited by mercuric ions,p-chloromercuribenzoate, and iodoacetic acid. It was inhibited slightly by EDTA and 1,10-phenanthroline. The enzyme was not inhibited by mercaptoethanol, dithiothreitol, fluoride, bromide, or chloride ions. Activity was lost after precipitation with ethanol, and after concentration with Lyphogel, Sephadex G-15, or lyophilization, but no activity was lost after precipitation with ammonium sulfate. Calcium ions did not activate the enzyme. Maltose was the best inducer of the enzyme. All the saccharides tested induced the enzyme slightly. No phosphorylase was found associated with the organism. However, a phosphatase and possibly an α-glucosidase were produced by the organism. The properties of the starch-degrading enzyme(s) ofCorynebacterium diphtheriae typegravis resemble those of either an amylase, an α-glucosidase, or both.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02328098
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