![Sample our Medicine, Dentistry, Nursing & Allied Health journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5944/TOC-Subject-Sample-2021-Medicine-Dentistry-Nursing-Allied-Health.jpg"})
Abstract
The enzyme deoxyuridine 5′-triphosphate nucleotidohydrolase (dUTPase) catalyses the hydrolysis of dUTP to dUMP and PPi thus controlling the incorporation of uracil into DNA genomes. In Campylobacter jejuni dUTPase exhibits structural properties of dimeric proteins characteristic of protozoa of the Kinetoplastidae family. In the present study we perform a kinetic analysis of Campylobacter dUTPase using the continuous spectrophotometric method and show that the enzyme is highly specific for deoxyuridine nucleotides. The Michaelis-Menten constant for dUTP was 0.66 μM while the kcat was 12.3 s− 1. dUDP was also efficiently hydrolysed although the specificity constant, kcat/Km, was five fold lower than for dUTP. The reaction product and the non hydrolysable analogue α,β imido dUDP are potent inhibitors of the enzyme while several analogues of dUMP with substituents at the 3′- and 5′-positions active against trimeric dUTPases, show poor inhibitory activity. Apparent structural and kinetic differences with other eukaryotic dUTPases suggest that the present enzyme might be exploited as a target for new drugs against campylobacteriosis.
Acknowledgements
We would like thank Medivir AB for contributing to the synthesis of the tritylated analogues. We would like to acknowledge the European Union LIFE programme (ICA4-CT-2001-00305), the Plan Nacional de Investigación (SAF2004-03828), the Plan Andaluz de Investigación (Cod. CVI-199) and the FIS Network RD06/0021 for funding. Antonio E. Vidal is a Postdoctoral scientist of the Ramon & Cajal programme.
