Abstract
Pyrolysis-gas chromatography-mass spectrometry of polyamino acids, proteins and complex proteinaceous material was used to study the flash pyrolytic behaviour of aliphatic amino acid moieties. Two types of highly specific compounds, tentatively identified as 3,5-alkyl-3,4-dihydro-2H-pyrrole-2,4-diones and 3-alkenyl-5-alkyl-pyrrolidine-2,4-diones on the basis of gas chromatographic retention times and high resolution mass spectrometric data, contain sequence information on pairs of aliphatic amino acid moieties (valine, leucine, isoleucine, alanine). The results can be applied to screen the presence or absence of adjacent aliphatic amino acid moieties in complex mixtures containing proteins or in purified proteins. The method is rapid, no treatment of the sample is required and very small amounts of sample are sufficient.