Peptide Mapping Analysis (EXP-204P)

SDS gel electrophoresis is used extensively to separate and identify denatured proteins. However, because this method relies on protein size alone, little information about proteins with the same molecular weight can be obtained. Peptide mapping is one of a number of techniques used to study the relatedness of similarly sized proteins. With this method, proteases are used to cut proteins into smaller peptide fragments and the fragments derived from two or more proteins are compared. The number and size of fragments generated from a protein are determined largely by the protein’s amino acid sequence, since proteases break peptide bonds adjacent to preferred amino acid residues. In this exercise, students use peptide mapping to compare the structural relatedness of serum albumin from the human, cow, chicken and pigeon. Typical results of the exercise are shown.

Precast polyacrylamide gels can be ordered from Bio Rad, (800-424-6723) Their catalog number is 1611177.