What is denaturing sds page?

Answer 1

Sodium dodecyl sulphate (SDS) is an anionic detergent which denatures proteins by "wrapping around" the polypeptide backbone - and SDS binds to proteins fairly specifically in a mass ratio of 1.4:1. In so doing, SDS confers a negative charge to the polypeptide in proportion to its length - ie: the denatured polypeptides become "rods" of negative charge cloud with equal charge or charge densities per unit length. It is usually necessary to reduce disulphide bridges in proteins before they adopt the random-coil configuration necessary for separation by size: this is done with 2- mercaptoethanol or dithiothreitol. In denaturing SDS-PAGE separations therefore, migration is determined not by intrinsic electrical charge of the polypeptide, but by molecular weight

And for the actual experiment beyond the denaturing: PAGE stands for polyacylamide gel electrophoresis. This is a procedure that separates proteins by size by running them through a gel "matrix" so that the smaller ones travel faster that the larger ones. This is achieved by creating an electric field with the sds-protein complex traveling toward the positively charged end of the gel. Once the smallest proteins have traveled most of the way across the gel the current is turned of and the gel is removed and stained with dye that binds protein so that you can see where it is in the gel.