Gel electrophoresis of amylose in the presence of sodium dodecyl sulfate.
It has been shown that sodium dodecyl sulfate (SDS) is capable of forming stable complexes with amylose and that fractionation of short-chain amyloses can be effected by SDS-gel electrophoresis.  Using a well-defined smylose fraction (molecular weight 4,000), the thermodynamic parameters pertaining to SDS-amylose interaction have been evaluated by means of frontal gel chromatography.  The results are as follows: association constant (K)=5.0 times 10-3-M-minus 1 at 25 degrees (pH 9.4); standard free energy change (delta G degrees)=-5.1 kcal/mole; standard enthalpy change (delta H degrees)=-5.8 kcal/mole; standard entropy change (delta Sdegrees)=-2.3(e.u.) and the maximum number of binding sites for SDS (n)=1.  In the presence of 0.5--1 percent SDS, amylose migrates toward the anode upon gel electrophoresis, giving a compact band.  High resolution of amylose fractions (released by treatment of amylopectin with debranching enzyme) has been attained using pore-size gradient gel electrophoresis.
D000688:Amylose / Q000302:isolation & purification*; D001665:Binding Sites; D002151:Calorimetry; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008722:Methods; D008970:Molecular Weight; D012967:Sodium Dodecyl Sulfate; D013816:Thermodynamics
D012967:Sodium Dodecyl Sulfate; D000688:Amylose