Bacterial IMPDH (Staphylococcus aureus)
(EC 1.1.1.205)

Synonyms: inosine 5'-monophosphate dehydrogenase, IMP dehydrogenase

NOVOCIB's bacterial IMPDH is a cloned protein of 53kDa cloned by PCR amplification of guaB gene of Staphylococcus aureus and expressed in E. coli.

Today, antibiotic resistance is one of the world’s most important public health problems. There is an urgent need for new antibiotic compounds acting on new targets. One attractive strategy for developing new antibiotics consists in inhibiting bacterial IMPDH, an enzyme involved in the de novo synthesis of purine nucleotides, and therefore, necessary for bacterial cell growth and division.

Mammalian and bacterial IMPDHs are known to have significantly different kinetic properties and inhibitor sensitivities^(1,2). The experiments done with previously cloned human IMPDH2 and bacterial IMPDH of Staphylococcus aureus, are illustrated below. In agreement with published data, mycophenolic acid (MPA) inhibits human IMPDH type II >20-times more efficiently than bacterial IMPDH with IC₅₀ values of 100nM and 2.6µM respectively (A). In contrast, mizoribine monophosphate displays the opposite selectivity (B). It is a more potent inhibitor of bacterial IMPDH with respective IC₅₀ values of 12nM and 185nM for bacterial and human enzymes.