Model systems for the 330 nm chromophore of pyridoxal 5'- phosphate containing enzymes

The absorption, fluorescence and chemical properties of the PLP site in enzymes can be simulated by model systems (9). The emphasis of this dissertation is the development of model systems for the three structures; carbinolamine, non-ionic hydrogen bonded Schiff base and substituted aldimine, proposed for the 330-335 nm chromophore of PLP containing enzymes. The PLI adducts with di- and triethylam ine were studied as models for the carbinolamine structure; the PLP adducts with t-butylarine and n-hexylamine were shown to be models for the Schiff base; and the adducts between diaminopropane and pyridine-4-aldehyde and benzaldehyde were studied as a model of the substituted aldimines structure.Chemical and physical properties of these model systems are presented and discussed in relation to PLP adducts with enzymes. Absorbance, infrared, fluorescence and NMR spectra were used to characterize the adducts. The effects of different solvents (DMSO and H„0) on PLP-amine adducts are reported and discussed.