Structural Basis and Binding Kinetics of Vaborbactam in Class A β-Lactamase Inhibition.
Structural Basis and Binding Kinetics of Vaborbactam in Class A β-Lactamase Inhibition.
复制标题
A 类 β-内酰胺酶抑制中 Vaborbactam 的结构基础和结合动力学。
DOI：
10.1128/aac.00398-20
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发表时间：
2020
影响因子：
4.9
通讯作者：
Chen,Yu
中科院分区：
文献类型：
--
作者：
Pemberton,OrvilleA;Tsivkovski,Ruslan;Totrov,Maxim;Lomovskaya,Olga;Chen,Yu
A 类 β-内酰胺酶是革兰氏阴性菌产生 β-内酰胺耐药性的主要原因。最近 FDA 批准的环硼酸伐硼巴坦是 A 类 β-内酰胺酶的可逆共价抑制剂，包括临床上经常观察到的 CTX-M 超广谱 β-内酰胺酶和 KPC 碳青霉烯酶。有趣的是，尽管这两种酶相似，但 Vaborbactam 对这两种酶表现出不同的结合动力学和细胞活性。 CTX-M-14 的 1.0-Å 晶体结构表明两个催化残基 K73 和 E166 分别带正电和中性。同时，KPC-2 的 1.25-Å 晶体结构揭示了与 CTX-M-14 相比，vaborbactam 更紧凑的结合模式，以及 W105 的替代构象。结合 W105 突变体的动力学分析，该结构证明了该残基和 β3 链的异常构象对失活率的影响，以及与 S70 的可逆共价键的稳定性。此外，KPC-2 S130G 突变体的研究揭示了 S130 对伐波巴坦与阿维巴坦（另一种最近批准的 β-内酰胺酶抑制剂）结合的不同影响。总而言之，这些新数据为伐硼巴坦的抑制机制和环硼酸酯抑制剂的未来发展提供了有价值的见解。
Class A β-lactamases are a major cause of β-lactam resistance in Gram-negative bacteria. The recently FDA-approved cyclic boronate vaborbactam is a reversible covalent inhibitor of class A β-lactamases, including CTX-M extended-spectrum β-lactamase and KPC carbapenemase, both frequently observed in the clinic. Intriguingly, vaborbactam displayed different binding kinetics and cell-based activity for these two enzymes, despite their similarity. A 1.0-Å crystal structure of CTX-M-14 demonstrated that two catalytic residues, K73 and E166, are positively charged and neutral, respectively. Meanwhile, a 1.25-Å crystal structure of KPC-2 revealed a more compact binding mode of vaborbactam versus CTX-M-14, as well as alternative conformations of W105. Together with kinetic analysis of W105 mutants, the structures demonstrate the influence of this residue and the unusual conformation of the β3 strand on the inactivation rate, as well as the stability of the reversible covalent bond with S70. Furthermore, studies of KPC-2 S130G mutant shed light on the different impacts of S130 in the binding of vaborbactam versus avibactam, another recently approved β-lactamase inhibitor. Taken together, these new data provide valuable insights into the inhibition mechanism of vaborbactam and future development of cyclic boronate inhibitors.