FORMATION OF QUINOXALINE FLUOPESCENT DERIVATIVES ON N-TERMINALS OF PROTEINS AND PEPTIDES
肽链及蛋白质N-末端喹喔啉类荧光衍生物的形成

The reaction of o-phenylenediamine with Oxoacyl groups on N terminals of the Dixon transaminated proteins and peptides can produce quinoxaline fluorescent derivative, however, the process is somewhat slow. The emission maxima of quinoxaline derivatives of peptides are about 360-365nm with the excitation at about 292-305nm depending upon the kinds of composeed amino acid residues. The quinoxalinyl-insulin has its emission maximum at 353nm by excitation at 318nm. Changes of the fluorescence of quinoxaline derivatives on tripeptides in the ethyl-ene glycol solutions are comparatively different from each other, depending upon the different kinds of residues and the configurations. It appears that the quinoxaline fluorescent derivative on N ternimal of a protein or a peptide be used to study structures and functions of the molecules.