Reaction mechanism of macrolide 2'-phosphotransferase from Escherichia coli to the 2'-modified macrolide antibiotics

Abstract

Reaction mechanism of macrolide 2'-phosphotransferase [MPH(2')] from Escherichia coli to the 2'-modified macrolide antibiotics was analyzed by using microbioassay, nuclear magnetic resonance (NMR) spectrometric assay and mass spectrometry. It was found by microbioassay that the 2'-modified macrolide antibiotics as triacetyloleandomycin (TAO), erythromycin ethyl succinate (EME) and erythromycin estolate were inactivated with adenosine triphosphate (ATP) by MPH(2'). The NMR spectrometric assay for the analysis of the reaction with the 2'-modified macrolide antibiotics and MPH(2') was established using guanosine triphosphate, which was higher reaction rate than ATP, as a cofactor. It was clearly shown by NMR spectrometric assay and mass spectrometry that the C2'-side chain of TAO and EME was naturally released in phosphate buffer solution, and then, the C2' position was phosphorylated with GTP by MPH(2').