Bhattacharya Sourya, Junghare Vivek, Hazra Mousumi, Pandey Niteesh Kumar, Mukherjee Abirlal, Dhankhar Kunal, Das Neeladrisingha, Roy Partha, Dubey Ramesh Chandra, Hazra Saugata
Department of Bioscience and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667, India.
Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar 249404, Uttarakhand, India.
ACS Bio Med Chem Au. 2023 Feb 8;3(2):174-188. doi: 10.1021/acsbiomedchemau.2c00044. eCollection 2023 Apr 19.
β-lactamase production with vast catalytic divergence in the pathogenic strain limits the antibiotic spectrum in the clinical environment. Class A carbapenemase shares significant sequence similarities, structural features, and common catalytic mechanisms although their resistance spectrum differs from class A β-lactamase in carbapenem and monobactam hydrolysis. In other words, it limited the antibiotic treatment option against infection, causing carbapenemase-producing superbugs. Ftu-1 is a class A β-lactamase expressed by the strain, a potent causative organism of tularemia. The chromosomally encoded class A β-lactamase shares two conserved cysteine residues, a common characteristic of a carbapenemase, and a distinctive class in the phylogenetic tree. Complete biochemical and biophysical characterization of the enzyme was performed to understand the overall stability and environmental requirements to perform optimally. To comprehend the enzyme-drug interaction and its profile toward various chemistries of β-lactam and β-lactamase inhibitors, comprehensive kinetic and thermodynamic analyses were conducted using various β-lactam drugs. The dynamic property of Ftu-1 β-lactamase was also predicted using molecular dynamics (MD) simulation to compare its loop flexibility and ligand binding with other related class A β-lactamases. Overall, this study fosters a comprehensive understanding of Ftu-1, proposed to be an intermediate class by characterizing its kinetic profiling, stability by biochemical and biophysical methodologies, and susceptibility profiling. This understanding would be beneficial for the design of new-generation therapeutics.
致病菌株中产生的具有巨大催化差异的β-内酰胺酶限制了临床环境中的抗生素谱。A类碳青霉烯酶具有显著的序列相似性、结构特征和共同的催化机制，尽管它们在碳青霉烯和单环β-内酰胺水解方面的耐药谱与A类β-内酰胺酶不同。换句话说，它限制了针对感染的抗生素治疗选择，导致产生碳青霉烯酶的超级细菌。Ftu-1是由该菌株表达的一种A类β-内酰胺酶，该菌株是兔热病的一种强效致病生物。染色体编码的A类β-内酰胺酶共有两个保守的半胱氨酸残基，这是碳青霉烯酶的一个共同特征，并且在系统发育树中属于一个独特的类别。对该酶进行了完整的生化和生物物理表征，以了解其整体稳定性和最佳发挥作用所需的环境条件。为了理解酶与药物的相互作用及其对各种β-内酰胺和β-内酰胺酶抑制剂化学结构的作用情况，使用各种β-内酰胺药物进行了全面的动力学和热力学分析。还使用分子动力学（MD）模拟预测了Ftu-1β-内酰胺酶的动力学特性，以比较其环的灵活性以及与其他相关A类β-内酰胺酶的配体结合情况。总体而言，本研究通过对Ftu-1的动力学特征、生化和生物物理方法测定的稳定性以及药敏特征进行表征，促进了对它的全面理解，Ftu-1被认为是一个中间类别。这种理解将有助于新一代治疗药物的设计。
