IMPROVED CONDITIONS FOR THE REMOVAL OF 2-OXOACYL GROUPS FROM THE N-TERMINUS OF PROTEINS

Proteins with R-CO-CO-NH- at the N-terminus, rather than the usual R-C H(-NH3+)-CO-NH-, are produced by nonenzymic transamination and also oc cur in the pyruvoyl enzymes. The oxoacyl group may be specifically rem oved from a model peptide, in yields of 70-80%, by treating them in 0. 1 M phosphate buffer at 37 degrees C for 24 h with 25 mM of the N-phos phonoaethyl derivative of phenylene-1,2-diamine. This provides mild co nditions for the stepwise removal of N-terminal residues without denat uration. (C) 1998 Elsevier Science B.V. All rights reserved.