ON THE POSSIBILITY TO PREDICT SPECTRAL PR OPERTIES OF PYRIDOXAL-5'-PHOSPHATE ALDIMINES WITH AMINO-ACIDS AND SOME OF THEIR DERIVATIVES ARISING IN THE COURSE OF PYRIDOXAL-DEPENDENT ENZYMATIC-REACTIONS

Quantum-chemical parameters for pi-electronic approximation (PPP) have been selected to enable reliable spectral computations of pyridoxal-5 '-phosphate aldimines and quinoids with aminoacids that also possess h igh accuracy (a discrepancies between theory and experiment for the fi rst electronic transition do not exceed 0,1 eV). The selection has bee n based on comparing experimental spectral data with those, computed b y PPP-approximation, as well as on comparing pi-electronic structures computed by CNDO/S and PPP approximations. All the selections enable u s to predict, In the framework of pi-electronic approximation, spectra l properties of some transitional substances that arise (or may arise) in the course of pyridoxal-depending enzymatic alpha,beta and beta,ga mma-elimination reactions.