REACTION OF BOVINE PANCREATIC RIBONUCLEASE A WITH 6-CHLOROPURINE RIBOSIDE 5‘-MONOPHOSPHATE

The n.m.r. spectra of native S-peptide and of S-peptide II, a derivative obtained after reaction of bovine pancreatic ribonuclease A with 6-chloropurine riboside 5′-monophosphate, both in D₂O and in urea-d₄, were obtained with a 270 MHz Fourier transform spectrometer. From these spectra it was possible to assign most of the proton resonances of the peptide and the position of the labelling group, the α-NH₂ of Lys-1, was also deduced.