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The amylase gene-enzyme system of chickens. II. Biochemical characterization of allozymes

Gapusan, R.A., Yardley, D.G., Hughes, B.L.
Biochemical genetics 1990 v.28 no.11/12 pp. 553-560
chickens, alpha-amylase, allozymes, enzyme activity, enzyme inhibitors, amylopectin, amylose, potato starch, dextrins, glycogen, genetic polymorphism, substrate specificity, enzyme polymorphism
The chicken amylase allozymes, Amy(F) and Amy(S), were extracted from pancreatic tissues of Amy(F/F) and Amy(S/S) individuals and purified. Activities were measured under various reaction conditions (= treatments) to assess whether the allozymes were functionally different. The amylases had properties typical of alpha-amylases, i.e., both were inhibited by ethylenediaminetetraacetate and alpha-amylase inhibitor from wheat, had pH optima between 7.0 and 8.0, and could utilize a variety of substrates containing alpha 1,4 linkages. The amylases were also found to be inhibited by potassium phosphate buffer and p-chloromercuribenzoate. In terms of substrate specificity, both amylases could utilize all of the substrates tested with activity observed in the following order: amylopectin > potato starch > dextrin > glycogen > amylose. Statistical analysis indicated significant functional differences between the two allozymes in terms of specific activities, substrate specificities, and inhibitor sensitivities. Amy(F) had a significantly lower specific activity than did Amy(S). The amylases responded differently to the substrate amylose, with Amy(F) better able to digest this substrate. Amy(S) was less sensitive than Amy(F) to alpha-amylase inhibitor from wheat.