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Kinetic patterns of glucoamylase isozymes isolated from Aspergillus species
- Smiley, K.L., Hensley, D.E., Smiley, M.J., Gasdorf, H.J.
- Archives of biochemistry and biophysics 1971 v.144 no.2 pp. 694
- Aspergillus, glucan 1,4-alpha-glucosidase, biosynthesis, enzyme activity, enzyme kinetics, isozymes, molecular weight, starch, hydrolysis
- The existence of multiple forms of glucoamylase has been known for some time. However, little information is available to differentiate these isozymes other than their electrophoretic mobility. It has now been found that the two forms of glucoamylase from several different Aspergillus strains do differ in their rate of attack on starch and glycogen. The Michaelis constant of the least charged isozyme on glycogen approaches infinity, whereas on starch it is several times greater than the more charged form. On small oligosaccharides and maltose the two forms show the same Km and Vmax values. In addition to kinetic differences, the two isozyme forms differ in their molecular weight.