Amylopectin electrophoresis

Kent and coworkers briefly reported the detection, after application of zone electrophoresis in barbiturate and other buffers, of a number of neutral polysaccharides, although no details of mobilities were noted. In a borate buffer at pH 8.0, amylopectin was observed to migrate toward the cathode and to be stained red with iodine, whereas amylose is stained blue and remains stationary. 

J. M. Herrero-Martinez, P. J. Schoenmakers, and W. Th. Kok, Determination of the amylose-amylopectin ratio of starches by iodine-affinity capillary electrophoresis, J. Chromatogr. A, 1053 (2004) 227-234. 

Dextrins obtained on y-irradiation of starch have been found to contain appreciable proportions of unidentified carbonyl residues. The properties of starch for starch-gel electrophoresis were improved by y-irradiation. The decreases in viscosity and iodine-absorption values, as well as the increased reducing properties, indicated that amylose and amylopectin are degraded by y-irradiation in the same way as native starches. Although each of the amylose and amylopectin components of amylomaize starch in y-irradiated and untreated samples was hydrolysed by a-amylase to the same extent, y-irradiated amylose had a low p-amylolysis limit. /-Irradiated amylomaize and com starches were hydrolysed to greater extents by a-amylase as the radiation dose was increased, and differences were detected in the products of enzymic degradation of amylomaize and corn starches following y-radiolysis. The water-soluble dextrins formed on y-irradiation of maize starch have been examined. ... 

The mobility of malted-barley a-amylase on electrophoresis in polyacrylamide gels containing starch or amylose or the P-limit dextrin from amylopectin was retarded completely at low concentrations of the enzyme, but it was not affected at high concentrations. ... 

An exo-enzyme (mol. wt. 5.4 x 10 ) isolated from Aerobacter aerogenes has been purified to homogeneity by disc electrophoresis, ion-exchange chromatography, and gel filtration. The enzyme is stable over a wide range of pH, and at its optimum pH (6.80) and temperature (50 °C) it hydrolysed starch, amylose, and amylopectin to maltohexaose, but it did not hydrolyse cyclohexa- or... 

A purified extracellular cyclodextrin D-glucanotransferase (pH optimum 4.6, pi 5A, mol. wt. 8.8 x 10 ) from an alkaliphilic Bacillus species has been shown to be a single homogeneous protein by polyacrylamide gel electrophoresis and ultracentrifugation. The Km values for cyclohexa-, cyclohepta-, and cyclo-octa-amyloses at a constant concentration of sucrose are 5.88, 0.39, and 0.25 mmol 1, respectively. The enzyme converted starch, amylopectin, glycogen, and amylopectin j8-limit dextrin into cyclodextrins. 

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