Filamenting temperature-sensitive mutant Z inhibitors from Glycyrrhiza glabra and their inhibitory mode of action

Synthesis of epitope-targeting nanobody based on native protein-protein interactions for FtsZ filamentation suppressor

Phage display and biopanning are powerful tools for generating binding molecules for a specific target. However, the selection process based only on binding affinity provides no assurance for the antibody's affinity to the target epitope. In this study, we propose a molecular-evolution approach guided by native protein-protein interactions to generate epitope-targeting antibodies. The binding-site sequence in a native protein was grafted into a complementarity-determining region (CDR) in the nanobody, and a nonrelated CDR loop (in the grafted nanobody) was randomized to create a phage display library. In this construction of nanobodies by integrating graft and evolution technology (CAnIGET method), suitable grafting of the functional sequence added functionality to the nanobody, and the molecular-evolution approach enhanced the binding function to inhibit the native protein-protein interactions. To apply for biological tool with growth screening, model nanobodies with an affinity for filamenting temperature-sensitive mutant Z (FtsZ) from Staphylococcus aureus were constructed and completely inhibited the polymerization of FtsZ as a function. Consequently, the expression of these nanobodies drastically decreased the cell division rate. We demonstrate the potential of the CAnIGET method with the use of native protein-protein interactions for steady epitope-specific evolutionary engineering.

Models versus pathogens: how conserved is the FtsZ in bacteria?

Combating anti-microbial resistance by developing alternative strategies is the need of the hour. Cell division, particularly FtsZ, is being extensively studied for its potential as an alternative target for anti-bacterial therapy. Bacillus subtilis and Escherichia coli are the two well-studied models for research on FtsZ, the leader protein of the cell division machinery. As representatives of gram-positive and gram-negative bacteria, respectively, these organisms have provided an extensive outlook into the process of cell division in rod-shaped bacteria. However, research on other shapes of bacteria, like cocci and ovococci, lags behind that of model rods. Even though most regions of FtsZ show sequence and structural conservation throughout bacteria, the differences in FtsZ functioning and interacting partners establish several different modes of division in different bacteria. In this review, we compare the features of FtsZ and cell division in the model rods B. subtilis and E. coli and the four pathogens: Staphylococcus aureus, Streptococcus pneumoniae, Mycobacterium tuberculosis, and Pseudomonas aeruginosa. Reviewing several recent articles on these pathogenic bacteria, we have highlighted the functioning of FtsZ, the unique roles of FtsZ-associated proteins, and the cell division processes in them. Further, we provide a detailed look at the anti-FtsZ compounds discovered and their target bacteria, emphasizing the need for elucidation of the anti-FtsZ mechanism of action in different bacteria. Current challenges and opportunities in the ongoing journey of identifying potent anti-FtsZ drugs have also been described.

Natural source, bioactivity and synthesis of 3-Arylcoumarin derivatives

3-arylcoumarins with different pharmacological properties widely exist in a variety of natural plants. The extensive research on 3-arylcoumarins was attributed to its therapeutic and relatively easy isolation. Therefore, 3-arylcoumarins can be recognised as useful structures for the design of novel compounds with potential pharmacological interest, particularly in the fields of anti-inflammatory, anti-cancer, antioxidant, Monoamine oxidase (MAO) enzyme inhibition, etc. The current review highlights the biological activities, design, and chemical synthetic methods of 3-arylcoumarins derivatives as well as their important natural product sources.

Targeting the Achilles Heel of FtsZ: The Interdomain Cleft

Widespread antimicrobial resistance among bacterial pathogens is a serious threat to public health. Thus, identification of new targets and development of new antibacterial agents are urgently needed. Although cell division is a major driver of bacterial colonization and pathogenesis, its targeting with antibacterial compounds is still in its infancy. FtsZ, a bacterial cytoskeletal homolog of eukaryotic tubulin, plays a highly conserved and foundational role in cell division and has been the primary focus of research on small molecule cell division inhibitors. FtsZ contains two drug-binding pockets: the GTP binding site situated at the interface between polymeric subunits, and the inter-domain cleft (IDC), located between the N-terminal and C-terminal segments of the core globular domain of FtsZ. The majority of anti-FtsZ molecules bind to the IDC. Compounds that bind instead to the GTP binding site are much less useful as potential antimicrobial therapeutics because they are often cytotoxic to mammalian cells, due to the high sequence similarity between the GTP binding sites of FtsZ and tubulin. Fortunately, the IDC has much less sequence and structural similarity with tubulin, making it a better potential target for drugs that are less toxic to humans. Over the last decade, a large number of natural and synthetic IDC inhibitors have been identified. Here we outline the molecular structure of IDC in detail and discuss how it has become a crucial target for broad spectrum and species-specific antibacterial agents. We also outline the drugs that bind to the IDC and their modes of action.

Pharmacological Activities of Coumarin Compounds in Licorice: A Review

Licorice is a traditional medicine commonly used in China and many other countries. Over the last 50 years, the structure and pharmacological effects of coumarin compounds in licorice have been investigated. However, a comprehensive review of the literature summarizing current trends is currently lacking. Thus, the aim of the present review is to provide an up-to-date summary of the scientific literature regarding the pharmacological effects of coumarin compounds in licorice, thereby laying the foundation for further research and optimal utilization of licorice. We retrieved 111 articles on the coumarin components of licorice and their potential pharmacological effects, based on titles, keywords, and abstracts from databases (including PubMed and Web of Science). Glycycoumarin, isoglycycoumarin, licoarylcoumarin, licopyranocoumarin, glycyrin, isotrifoliol, glycyrol, and glycyrurol have been investigated for their anticancer, hepatoprotective, antispasmodic, immunosuppressive, anti-inflammatory, and antibacterial properties, and use as therapeutic agents in metabolic syndrome, thereby demonstrating their potential for clinical applications. Future research should further explore the pharmacological mechanisms of action of coumarin compounds, including their antibacterial activities. Investigations into the pharmacological activities of different glycycoumarin isomers might open new research frontiers.

Synthesis and Docking Study of N-(Cinnamoyl)-N'-(substituted)acryloyl Hydrazide Derivatives Containing Pyridinium Moieties as a Novel Class of Filamentous Temperature-Sensitive Protein Z Inhibitors against the Intractable Xanthomonas oryzae pv. oryzae Infections in Rice

Xanthomonas oryzae pv. oryzae (Xoo) is an offensive phytopathogen that can invade a wide range of plant hosts to develop bacterial diseases, including the well-known rice bacterial leaf blight. However, few agrochemicals have been identified to effectively prevent and eliminate Xoo-induced diseases. Thus, designing novel antibacterial compounds on the basis of the potential targets from Xoo may lead to the discovery of highly efficient and innovative anti-Xoo agents. Filamentous temperature-sensitive protein Z (FtsZ), an important functional protein in the progression of cell division, has been widely reported and exploited as a target for creating antibacterial drugs in the field of medicine. Therefore, the fabrication of innovative frameworks targeting XooFtsZ may be an effective method for managing bacterial leaf blight diseases via blocking the binary division and reproduction of Xoo. As such, a series of novel N-(cinnamoyl)-N'-(substituted)acryloyl hydrazide derivatives containing pyridinium moieties were designed, and the anti-Xoo activity was determined. The bioassay results showed that compound A₇ had excellent anti-Xoo activity (EC₅₀ = 0.99 mg L^-1) in vitro and distinct curative activity (63.2% at 200 mg L^-1) in vivo. Further studies revealed that these designed compounds were XooFtsZ inhibitors, validating by the reduced GTPase activity of recombinant XooFtsZ, the nonfilamentous XooFtsZ assembly observed in the TEM images, and the prolonged Xoo cells from the fluorescence patterns. Computational docking studies showed that compound A₇ had strong interactions with ASN34, GLN193, and GLN197 residues located in the α helix regions of XooFtsZ. The present study demonstrates the developed FtsZ inhibitors can serve as agents to control Xoo-induced infections.