Mechanistic insight into PhnZ from kinetic isotope effects

The ACS journal Biochemistry has a very long and distinguished history in publishing studies on enzyme mechanisms. In 2019 our lab had the privilege to be invited by John Gerlt (U. Illinois) to submit a manuscript to be part of a dedicated issue on “Current Topics in Mechanistic Enzymology“. This was a huge thrill for me personally as John is a legend in the field of enzyme catalysis. The special issue was finally published in December of 2019, which includes our paper describing the use of deuterium kinetic isotope effects to parse out the features of the transition state for the phosphonate degrading enzyme PhnZ. Surprisingly, C-H bond cleavage, rather than C-P bond cleavage is rate limiting for PhnZ. This was a very technically challenging study that was led by postdoc Simanga Gama and included massive efforts from grad students Becky Lo and Jacqueline Séguin, as well as synthetic wizardry from Profs Katharina Pallitsch and Friedrich Hammerschmidt (U. Vienna). Well done everyone!

PhnZ TOC graphic C-H bond cleavage

Gama, S. R., Lo, B. S. Y., Séguin, J., Pallitsch, K., Hammerschmidt, F., and Zechel, D. L. (2019) C-H Bond Cleavage Is Rate-Limiting for Oxidative C-P Bond Cleavage by the Mixed Valence Diiron-Dependent Oxygenase PhnZ. Biochemistry. 58, 5271–5280

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