Description:This volume is a summary of the proceedings of the 8th International Symposium on Vitamin B6 and Carbonyl Catalysis, held in Osaka, Japan, 15-19 October 1990. The development of molecular biology and x-ray crystallography techniques have contributed greatly to the knowledge and understanding of PLP-dependent enzymes. The structural, mechanistic and functional aspects of the PLP-dependent enzymes have been studied for over 40 years by many active researchers. Recent evidence indicates that the coenzyme is substituted by the pyruvoyl group which is a reactive carbonyl in some amino acid decarboxylases, and the presence of pyrroloquinoline quinone (PQQ), another carbonyl coenzyme, in other enzymes. The contents of this volume attest to the exciting progress in elucidating structure, mechanism of action, and the function of enzymes dependent on coenzymes containing the carbonyl group