Binding order of substrate and cofactor in sulfonamide monooxygenase during sulfa drug degradation: in silico studies.

For decades, sulfonamide antibiotics have been used across industries such as agriculture and animal husbandry. However, the use and inadvertent misuse of these antibiotics have resulted in the advent of sulfonamide-drug-resistant strains due to antibiotic pollution. Enzymatic bioremediation of antibiotics remains a potential emerging solution to combat antibiotic pollution. Here, we propose an enzymatic model for the degradation of sulfonamides by Microbacterium sp. We have employed a multi-pronged computational strategy involving - protein structure modelling, ligand docking and molecular dynamics simulations to decipher a plausible binding order for the enzymatic degradation of sulfonamides by the bacterial sulfonamide monooxygenase, SulX. Our results enable us to predict that this degradation is achieved through the sequential binding of the antibiotic sulfonamide followed by the reduced flavin cofactor FMNH2, thereby laying the computational foundation for further advancements in enzyme-mediated degradation of the antibiotic. We also provide a list of experiments which may be performed to verify and follow-up on our in-silico studies.Communicated by Ramaswamy H. Sarma.

Spheroids formation in large drops suspended in superhydrophobic paper cones.

The utilization of 3D cell culture for spheroid formation holds significant implications in cancer research, contributing to a fundamental understanding of the disease and aiding drug development. Conventional methods such as the hanging drop technique and other alternatives encounter limitations due to smaller drop volumes, leading to nutrient starvation and restricted culture duration. In this study, we present a straightforward approach to creating superhydrophobic paper cones capable of accommodating large volumes of culture media drops. These paper cones have sterility, autoclavability, and bacterial repellent properties. Leveraging these attributes, we successfully generate large spheroids of ovarian cancer cells and, as a proof of concept, conduct drug screening to assess the impact of carboplatin. Thus, our method enables the preparation of flexible superhydrophobic surfaces for laboratory applications in an expeditious manner, exemplified here through spheroid formation and drug screening demonstrations.

Proteomic Analysis of the Mycobacterium tuberculosis Outer Membrane for Potential Implications in Uptake of Small Molecules.

Increased resistance to current antimycobacterial agents and a potential bias toward relatively hydrophobic chemical entities highlight an urgent need to understand how current anti-TB drugs enter the tubercle bacilli. While inner membrane proteins are well-studied, how small molecules cross the impenetrable outer membrane remains unknown. Here, we employed mass spectrometry-based proteomics to show that octyl-ß-d-glucopyranoside selectively extracts the outer membrane proteins of Mycobacterium tuberculosis. Differentially expressed proteins between nutrient-replete and nutrient-depleted conditions were enriched to identify proteins involved in nutrient uptake. We demonstrate cell surface localization of seven new proteins using immunofluorescence and show that overexpression of the proteins LpqY and ProX leads to hypersensitivity toward streptomycin, while overexpression of SubI, SpmT, and Rv2041 exhibited higher membrane permeability, assessed through an EtBr accumulation assay. Further, proton NMR metabolomics suggests the role of six outer membrane proteins in glycerol uptake. This study identifies several outer membrane proteins that are involved in the permeation of small hydrophilic molecules and are potential targets for enhancing the uptake and efficacy of anti-TB drugs.

Global efforts on vaccines for COVID-19: Since, sooner or later, we all will catch the coronavirus

COVID-19 is an emerging infectious disease that has turned into a pandemic. It spreads through droplet transmission of the new coronavirus SARS-CoV-2. It is an RNA virus displaying a spike protein as the major surfaceprotein with significant sequence similarity to SARS-CoV which causes severe acute respiratory syndrome. Thereceptor binding domain of the spike protein interacts with the human angiotensin converting enzyme 2 and isconsidered as the antigenic determinant for stimulating an immune response. While multiple candidate vaccines arecurrently under different stages of development, there are no known therapeutic interventions at the moment. Thisreview describes the key genetic features that are being considered for generating vaccine candidates by employinginnovative technologies. It also highlights the global efforts being undertaken to deliver vaccines for COVID-19through unprecedented international cooperation and future challenges post development.