Molecular cloning and Biochemical characterization of pyridoxal 5’-phosphate dependent enzymes of unknown function

General introduction The main topic of this Ph.D. thesis is the characterization of gene products identified as PLP-dependent enzymes with unknown function. A complete and detailed description on function and evolution of PLP-dependent enzymes is provided in chapter 1. Chapter 2 describes the molecular cloning as well as the recombinant expression and the initial biochemical characterization of a threonine synthase homolog from mouse. Finally, in chapter 3 I describe the study of two recombinant human proteins homolog of alanine-glyoxylate amino transferase 2. The last part, Appendix, reports the evaluation of small RNA-cleaving DNAs (ribozymes), chemically modified by means of introduction of monomers of locked nucleic acids (LNA), in order to improve to cleavage of long and structured mRNAs.