Zur N-terminalen Konfiguration der Peptiduntereinheit im Protein des Tabakmosaikvirus

Abstract

By degradation of the TMV-protein with diymotrypsin and pepsin, the peptides Ala-Asp-Pro-Ileu-Glu-Leu and Asp-Pro-Leu-Val-Thr were isolated. They contained the sequences Pro-Ileu-Glu and Pro-Leu-Val, previously assumed to be N-terminal groups. Further, the structure of the acetyl-seryl-tyrosine-dipeptide found by NARITA was confirmed. In the isolated peptides and in synthetic α-aspartyl-proline-peptides the linkage between asp and pro is very labile to acidic hydrolysis. This explains why the proline sequences were found as terminal groups in the TMV protein after treatment with trichloroacetic acid. The ε-amino-groups of both lysine residues in the peptide chain react with fluorodinitrobenzene. Therefore a side-chain cannot be attached to these amino-groups. The results support a linear structure of the peptide chain with N-terminal acetyl-seryl-tyrosine as suggested by NARITA and FRAENKEL-CONRAT.