Background:

CHIR-090 is a very potent, low, tight-binding inhibitor of LpxC with Ki value of 4.0 nM [1].
LpxC is a zinc-dependent amidase and present in almost all Gram-negative bacteria. LpxC is a promising target for the development of novel antibiotic substances against multigrug-resistant Gram-negative bacteria [2].
CHIR-090 is a potent LpxC inhibitor and has a different selectivity with the reported LpxC inhibitor L-161. When tested with Escherichia coli LpxC, administration of CHIR-090 showed tight inhibition with Ki value of 4.0 nM, Ki*=0.5 nM, K5=1.9/min and K6=0.18/min [1]. In bacterial P.aeruginosa efflux pupm mutants, CHIR-090 treatment showed inhibition function on MexAB-Oprm, MexCD-OprJ and MexEF-OprN [2]. CHIR-090 showed remarkable antibiotic activity against both E.coli and P.aeruginosa by inhibiting LpxC orthologs at low nM concentrations [3].
In E.coli W3110RL with R.legumunosarum lpxC replacement of E.coli lpxC, CHIR-090 (1 to 10 μg/ml) treatment had no effect on strain growth on LB agar plates while wild-type cells stopped growing after about 2 h in the presence of 1 μg/ml CHIR-090 [1].
参考文献:
[1].Barb, A.W., et al., Inhibition of lipid A biosynthesis as the primary mechanism of CHIR-090 antibiotic activity in Escherichia coli. Biochemistry, 2007. 46(12): p. 3793-802.
[2].Barb, A.W. and P. Zhou, Mechanism and inhibition of LpxC: an essential zinc-dependent deacetylase of bacterial lipid A synthesis. Curr Pharm Biotechnol, 2008. 9(1): p. 9-15.
[3].McClerren, A.L., et al., A slow, tight-binding inhibitor of the zinc-dependent deacetylase LpxC of lipid A biosynthesis with antibiotic activity comparable to ciprofloxacin. Biochemistry, 2005. 44(50): p. 16574-83.