InBioS, Center for Protein Engineering, Biological Macromolecules, Department of Life Sciences, University of Liège, Liège, Belgium.
InBioS, Center for Protein Engineering, NEPTUNS, Department of Life Sciences, University of Liège, Liège, Belgium.
Antimicrob Agents Chemother. 2023 Apr 18;67(4):e0149922. doi: 10.1128/aac.01499-22. Epub 2023 Mar 9.
Three soluble single-domain fragments derived from the unique variable region of camelid heavy-chain antibodies (VHHs) against the CMY-2 β-lactamase behaved as inhibitors. The structure of the complex VHH cAb(254)/CMY-2 showed that the epitope is close to the active site and that the CDR3 of the VHH protrudes into the catalytic site. The β-lactamase inhibition pattern followed a mixed profile with a predominant noncompetitive component. The three isolated VHHs recognized overlapping epitopes since they behaved as competitive binders. Our study identified a binding site that can be targeted by a new class of β-lactamase inhibitors designed on the sequence of the paratope. Furthermore, the use of mono- or bivalent VHH and rabbit polyclonal anti-CMY-2 antibodies enables the development of the first generation of enzyme-linked immunosorbent assay (ELISA) for the detection of CMY-2 produced by CMY-2-expressing bacteria, irrespective of resistotype.
三种可溶性的单域片段来源于针对 CMY-2 β-内酰胺酶的骆驼重链抗体（VHH）的独特可变区，表现出抑制作用。VHH cAb(254)/CMY-2 复合物的结构表明，抗原表位接近活性位点，并且 VHH 的 CDR3 突出到催化位点中。β-内酰胺酶抑制模式呈现出以非竞争性成分为主的混合模式。三种分离的 VHH 识别重叠的抗原表位，因为它们表现为竞争性结合物。我们的研究确定了一个可以作为针对变构部位序列设计的新型β-内酰胺酶抑制剂的靶标结合位点。此外，使用单价或二价 VHH 和兔多克隆抗 CMY-2 抗体可以开发第一代酶联免疫吸附测定（ELISA），用于检测由表达 CMY-2 的细菌产生的 CMY-2，而与耐药型无关。
