Sensitization of amino acid derivatives obtained from Edman degradation with radioactively-labeled iodohistamine.

ABSTRACT

The minimum amount of proteins and peptides required for sequencing is constantly decreasing as more sensitive microsequencing methods are developed. The sensitization of and Edman degradation product is one such method. We took the 2-anilino 5-thiazolinone amino acid intermediates obtained from Edman degradation by conventional sequencing procedures, and quantitatively reacted them with a primary amine. The amine used was radioactive [125I]iodohistamine, which affords highly sensitive detection. The labeled amino acid derivatives were separated by thin layer chromatography. Ten femtomoles of a labeled derivative can be detected by autoradiography.