Pullulanase pattern

Modified substrates may be used in testing the action patterns of purified enzymes. Thus, periodate-oxidized laminaran was used by Smith and coworkers to show the exo action of Basidiomycete (l- 3)-j8-n-glucanase. The oxidized-amylose substrate described earlier (see p. 266) has been used with alpha- and heta-amylases to illustrate how the method is completely general, and applicable to all classes of polysaccharides and poIysaccharidases. ° By use of oxidized pullulan, the endo nature of pullulanase action was confirmed. ... 

An a-amylase found in the culture filtrate of a strain of Thermoactinomyces vulgaris was purified by ammonium sulphate fractionation, and ion-exchange chromatographies.The purified enzyme showed a single band on disc gel electrophoresis. The pH optimum, temperature optimum, and isoelectric point were pH 5.0, 70 C, and pi 5.2, respectively. The a-amylase was stabilized by Ca and was found to hydrolyse pullulan to panose. Therefore, the hydrolytic pattern of this enzyme is different from those of pullulanase and isopullulanase. 

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