The Selective Degradation of Wheat Gluten

A method believed to hydrolyze peptide bonds of proteins selectively at the amino groups of serine was used to obtain polypeptides from wheat gluten. The procedure involved the use of strong acid and introduced appreciable amounts of sulphur into the products possibly as sulphonic acid groups. Most of the serine appeared at the amino termini of the peptides. The peptides displayed a striking electrophoretic homogeneity which may at least in part be accounted for by the acquired acid groups. Osmotic pressure measurements indicated an average molecular weight near 20,000 and terminal group estimates indicate that each molecule contained several N-terminal serine residues. There appeared to be strong association or chemical cross linking between peptide chains of the degraded gluten.