title: Molecular basis of NDM-1, a new antibiotic resistance determinant.
abstract: The New Delhi Metallo-β-lactamase (NDM-1) was first reported in 2009 in a Swedish patient. A recent study reported that Klebsiella pneumonia NDM-1 positive strain or Escherichia coli NDM-1 positive strain was highly resistant to all antibiotics tested except tigecycline and colistin. These can no longer be relied on to treat infections and therefore, NDM-1 now becomes potentially a major global health threat.In this study, we performed modeling studies to obtain its 3D structure and NDM-1/antibiotics complex. It revealed that the hydrolytic mechanisms are highly conserved. In addition, the detailed analysis indicates that the more flexible and hydrophobic loop1, together with the evolution of more positive-charged loop2 leads to NDM-1 positive strain more potent and extensive in antibiotics resistance compared with other MBLs. Furthermore, through biological experiments, we revealed the molecular basis for antibiotics catalysis of NDM-1 on the enzymatic level. We found that NDM-1 enzyme was highly potent to degrade carbapenem antibiotics, while mostly susceptible to tigecycline, which had the ability to slow down the hydrolysis velocity of meropenem by NDM-1. Meanwhile, the mutagenesis experiments, including D124A, C208A, K211A and K211E, which displayed down-regulation on meropenem catalysis, proved the accuracy of our model.At present, there are no effective antibiotics against NDM-1 positive pathogen. Our study will provide clues to investigate the molecular basis of extended antibiotics resistance of NDM-1 and then accelerate the search for new antibiotics against NDM-1 positive strain in clinical studies.
authors: Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
authors: Zhongjie
authors: Z
authors: Liang
authors: Lianchun
authors: L
authors: Li
authors: Yuanyuan
authors: Y
authors: Wang
authors: Limin
authors: L
authors: Chen
authors: Xiangqian
authors: X
authors: Kong
authors: Yao
authors: Y
authors: Hong
authors: Lefu
authors: L
authors: Lan
authors: Mingyue
authors: M
authors: Zheng
authors: Cai
authors: C
authors: Guang-Yang
authors: Hong
authors: H
authors: Liu
authors: Xu
authors: X
authors: Shen
authors: Cheng
authors: C
authors: Luo
authors: Keqin Kathy
authors: KK
authors: Li
authors: Kaixian
authors: K
authors: Chen
authors: Hualiang
authors: H
authors: Jiang
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D055162:Biocatalysis / Q000187:drug effects; D015780:Carbapenems / Q000737:chemistry / Q000494:pharmacology; D017124:Conserved Sequence; D004352:Drug Resistance, Microbial / Q000187:drug effects; D057075:Enzyme Assays; D006868:Hydrolysis / Q000187:drug effects; D000077731:Meropenem; D008958:Models, Molecular; D017354:Point Mutation / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D016415:Sequence Alignment; D040681:Structural Homology, Protein; D013845:Thienamycins / Q000737:chemistry / Q000494:pharmacology; D015032:Zinc / Q000378:metabolism; D001618:beta-Lactamases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D013845:Thienamycins; C434285:beta-lactamase FEZ-1; C425108:beta-lactamase bla(vim-2); D001618:beta-Lactamases; C552864:beta-lactamase NDM-1; D000077731:Meropenem; D015032:Zinc