Collect. Czech. Chem. Commun. 1985, 50, 2310-2318

Applicability of glutaminyl-tRNA cyclotransferase in the peptide synthesis

Václav Čeřovský and Karel Jošt

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Peptides with amino-terminal glutamine and their derivatives on treatment with crude papain preparation, containing glutaminyl-tRNA cyclotransferase (E.C., are converted into the corresponding compounds with pyroglutamic acid. This enzymic cyclization does not take place with glutamic acid or its γ-derivatives. The reaction has been optimized for the preparation of pyroglutamic acid phenylhydrazide. Glutaminyl-leucine phenylhydrazide and glutaminyl-histidyl-proline amide reacted to give pyroglutamyl-leucine phenylhydrazide and TRH, respectively. Treatment of crude papain with iodoacetamide completely inhibited its activity without affecting the glutaminyl-cyclotransferase activity.