Bisthiazolidines: A Substrate-Mimicking Scaffold as an Inhibitor of the NDM-1 Carbapenemase.
Pathogenic Gram-negative bacteria resistant to almost all β-lactam antibiotics are a major public health threat. Zn(II)-dependent or metallo-β-lactamases (MBLs) produced by these bacteria inactivate most β-lactam antibiotics, including the carbapenems, which are "last line therapies" for life-threatening Gram-negative infections. NDM-1 is a carbapenemase belonging to the MBL family that is rapidly spreading worldwide. Regrettably, inhibitors of MBLs are not yet developed. Here we present the bisthiazolidine (BTZ) scaffold as a structure with some features of β-lactam substrates, which can be modified with metal-binding groups to target the MBL active site. Inspired by known interactions of MBLs with β-lactams, we designed four BTZs that behave as in vitro NDM-1 inhibitors with Ki values in the low micromolar range (from 7 ± 1 to 19 ± 3 μM). NMR spectroscopy demonstrated that they inhibit hydrolysis of imipenem in NDM-1-producing Escherichia coli. In vitro time kill cell-based assays against a variety of bacterial strains harboring blaNDM-1 including Acinetobacter baumannii show that the compounds restore the antibacterial activity of imipenem. A crystal structure of the most potent heterocycle (L-CS319) in complex with NDM-1 at 1.9 Å resolution identified both structural determinants for inhibitor binding and opportunities for further improvements in potency.
Instituto de Biologı́a Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquı́micas y Farmacéuticas, Universidad Nacional de Rosario (UNR) , Ocampo y Esmeralda, 2000 Rosario, Argentina.
Mariano M
MM
González
School of Cellular and Molecular Medicine, Medical Sciences Building, University of Bristol , University Walk, Bristol BS8 1TD, United Kingdom.
Magda
M
Kosmopoulou
Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, and Departments of Pharmacology, Biochemistry, Microbiology, and Molecular Biology, Case Western Reserve University , Cleveland, Ohio 44106, United States.
Maria F
MF
Mojica
Laboratorio de Quı́mica Farmacéutica, Facultad de Quı́mica, Universidad de la República (UdelaR) , Montevideo 11800, Uruguay.
Valerie
V
Castillo
School of Cellular and Molecular Medicine, Medical Sciences Building, University of Bristol , University Walk, Bristol BS8 1TD, United Kingdom.
Philip
P
Hinchliffe
Department of Chemistry, University of Oxford, Chemistry Research Laboratory , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
Ilaria
I
Pettinati
Department of Chemistry, University of Oxford, Chemistry Research Laboratory , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
Jürgen
J
Brem
Department of Chemistry, University of Oxford, Chemistry Research Laboratory , 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
Christopher J
CJ
Schofield
Laboratorio de Quı́mica Farmacéutica, Facultad de Quı́mica, Universidad de la República (UdelaR) , Montevideo 11800, Uruguay.
Graciela
G
Mahler
Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, and Departments of Pharmacology, Biochemistry, Microbiology, and Molecular Biology, Case Western Reserve University , Cleveland, Ohio 44106, United States.
Robert A
RA
Bonomo
Instituto de Biologı́a Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquı́micas y Farmacéuticas, Universidad Nacional de Rosario (UNR) , Ocampo y Esmeralda, 2000 Rosario, Argentina.
Leticia I
LI
Llarrull
School of Cellular and Molecular Medicine, Medical Sciences Building, University of Bristol , University Walk, Bristol BS8 1TD, United Kingdom.
James
J
Spencer
Instituto de Biologı́a Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquı́micas y Farmacéuticas, Universidad Nacional de Rosario (UNR) , Ocampo y Esmeralda, 2000 Rosario, Argentina.
Alejandro J
AJ
Vila
NDM-1; antibiotic resistance; bisthiazolidines; inhibitors; metallo-β-lactamase