title: Gel electrophoresis of amylose in the presence of sodium dodecyl sulfate.
abstract: 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.
mesh_terms: 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
chemical_list: D012967:Sodium Dodecyl Sulfate; D000688:Amylose