Probing the role of Tyr 64 of Treponema denticola cystalysin by site-directed mutagenesis and kinetic studies

Tyr 64, hydrogen-bonded to coenzyme phosphate in Treponema denticola cystalysin is changed to alanine by site-directed mutagenesis, spectroscopic and kinetic properties of the Tyr 64 are investigated to explore the differences in coenzyme structure and kinetic mechanism to those of wild type enzyme. The result finds new insight into the catalytic mechanism of cystalysin and highlights the functional role of Tyr 64.