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Photophysical Study of Pyridoxal 5'-Phosphate and Its Schiff Base with n-Hexylamine |
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| Authors: | Gerardo R Echevarria Javier Catalán Francisco Garcia Bianco |
| Institution: | Departamento de Quimica Fisica, Universidad de Alcalá, Alcala de Henares, Spain;Departamento de Quimica Fisica Aplicada, Universidad Autónoma de Madrid, Madrid, Spain;Departamento de Quimica Fisica II, Universidad Complutense, Madrid, Spain |
| Abstract: | Abstract— Phosphopyridoxal enzymes exhibit a wide variety of reactions. The activation mechanism proceeds with the formation of Schiff bases that undergo loss or transfer of one or more protons. Changes in the fluorescent properties of the pyridoxal 5'-phosphate and its Schiff base may signal changes in the protonation state and/or in the microenvironment of the cofactor. In this paper the average fluorescence lifetime of pyridoxal 5'-phosphate (PLP) as a function of pH was studied in a medium of 0.1 M ionic strength at 25°C. The ionic species of PLP with an unprotonated hydrogen atom were found to exhibit fluorescence lifetimes in the region of 100 ps on excitation at λ= 390 nm. The average fluorescence lifetimes for PLP in its Schiff bases with n-hexylamine in media of low polarity are reported. |
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