ABSTRACT
Analysis of the various methylated amino acids by ion-exchange column chromatography can be divided into two categories, one employing an automatic amino acid analyzer and the other a manually operated system with solvent gradient. Prior to the analysis of the methylated amino acids in the acid-hydrolyzates of proteins or other biological materials, it is highly desired to partly purify the amino acids, particularly when paper or thin-layer chromatography is to be employed. A standard automatic amino acid analyzer is suited for the analysis of radiomethyl-labeled carboxyl methylesters. Analysis of aspartyl ß-methyl esters in the hydrolyzate can be performed by either automatic amino acid analyzer, paper chromatography, or electrophoresis in a similar manner as described for glutamyl γ-methyl ester. An analytical method of methylated amino acids based on the combined use of two-dimensional thin-layer chromatography and autoradiography has been introduced by Klagsbrun and Furano.
