Investigation into the Interaction between Penicillin-Resistant and Penicillin-Susceptible Gonococcal Penicillin-Binding Protein 2 and Target Phenolic Ligands through Molecular Docking Studies and Structure-Activity Relationship Analysis.

Gonococcal infections present a notable public health issue, and the major approach for treatment involves using ß-lactam antibiotics that specifically target penicillin-binding protein 2 (PBP2) in Neisseria gonorrhoeae. This study examines the influence of flavonoids, namely, rutin, on the structural changes of PBP2 in both penicillin-resistant (FA6140) and penicillin-susceptible (FA19) strains. The research starts by clarifying the structural effects of certain mutations, such as the insertion of an aspartate residue at position 345 (Asp-345a), in the PBP2. The strain FA6140, which is resistant to penicillin, shows specific changes that lead to a decrease in penicillin binding. These mutations, namely, P551S and F504L, have a significant impact on the pace at which acylation occurs and the stability of the strain under high temperatures. Molecular docking analyses investigate the antibacterial activities of rutin and other phytocompounds, emphasising rutin's exceptional binding affinity and its potential as an inhibitor of PBP2. Quercetin and protocatechuic acid have encouraging antibacterial effectiveness, with quercetin displaying characteristics similar to those of drugs. Molecular dynamics simulations offer a detailed comprehension of the interactions between flavonoids and PBP2, highlighting rutin's exceptional antioxidant effects and strong affinity for the substrate binding site. The study's wider ramifications pertain to the pressing requirement for antiviral treatments, namely, in the context of the ongoing COVID-19 epidemic. Flavonoids have a strong affinity for binding to PBP2, indicating their potential as inhibitors to impair cell wall formation in N. gonorrhoeae. Ultimately, this study provides extensive knowledge on the interactions between proteins and ligands, the dynamics of the structure, and the ability of flavonoids to combat penicillin-resistant N. gonorrhoeae bacteria. The verified simulation outcomes establish a basis for the creation of potent inhibitors and medicinal therapies to combat infectious illnesses.

Bridelia ferruginea inhibits key carbohydrate digesting enzyme and intestinal glucose absorption and modulates glucose metabolism in diabetic rats.

The antidiabetic potentials of the dichloromethene, ethyl acetate, butanol and aqueous fractions of Bridelia ferruginea leaves were investigated using in vitro, ex vivo and in vivo models. In vitro and ex vivo antidiabetic activities revealed the butanol (BFBF) to be the most active of the fractions, and thus selected for in vivo study. Diabetes was induced using the fructose-streptozotocin model. Treatments with BFBF significantly reduced blood glucose level and improved glucose tolerance, serum insulin level and sensitivity as well as suppressed hyperlipidaemia and serum nephropathy markers. Histopathological analysis revealed the ability of BFBF to protect and regenerate pancreatic ß-cells. BFBF significantly elevated glutathione level, catalase and superoxide dismutase activities, while depleting MDA level in serums and kidney of diabetic rats. Phenols, steroids, terpenoids, aliphatic and aromatic compounds were identified in the fractions following GC-MS analysis. Overall, results from this study propose that BFBF possess potent antidiabetic activity.

Protein PEGylation: Navigating Recombinant Protein Stability, Aggregation, and Bioactivity.

Enzymes play a powerful role as catalysts with high specificity and activity under mild environmental conditions. Significant hurdles, such as reduced solubility, reduced shelf-life, aggregate formation, and toxicity, are still ongoing struggles that scientists come across when purifying recombinant proteins. Over the past three decades, PEGylation techniques have been utilized to significantly overcome low solubility; increased protein stability, shelf-life, and bioactivity; and prevented protein aggregate formation. This review seeks to highlight the impact of PEG-based formulations that are significantly utilized to obtain favourable protein physiochemical properties. The authors further discuss other techniques that can be employed such as coexpression studies and nanotechnology-based skills to obtaining favourable protein physiochemical properties.

Recombinant Expression, Purification and PEGylation of DNA Ligases.

BACKGROUND: Reagent proteins such as DNA ligases play a central role in the global reagents market. DNA ligases are commonly used and are vital in academic and science research environments. Their major functions include sealing nicks by linking the 5'-phosphorylated end to a 3'-hydroxyl end on the phosphodiester backbone of DNA, utilizing ATP or NADP molecules as an energy source. OBJECTIVE: The current study sought to investigate the role of PEGylation on the biological activity of purified recombinant DNA ligases. METHODS: We produced two recombinant DNA ligases (Ligsv081 and LigpET30) using E. coli expression system and subsequently purified using affinity chromatography. The produced proteins wereconjugated to site specific PEGylation or non-specific PEGylation. FTIR and UV-VIS spectroscopy were used to analyze secondary structures of the PEG conjugated DNA ligases. Differential scanning fluorimetry was employed to assess the protein stability when subjected to various PEGylation conditions. RESULTS: In this study, both recombinant DNA ligases were successfully expressed and purified as homogenous proteins. Protein PEGylation enhanced ligation activity, increased transformation efficiency by 2-foldfor plasmid ligations and reduced the formation of protein aggregates. CONCLUSION: Taken together, site-specific PEGylation can potentially be explored to enhance the biological activity and stability of reagent proteins such as ligases.

In vitro and computational studies of the antioxidant and anti-diabetic properties of Bridelia ferruginea.

The leaves, stem and root bark of Bridelia ferruginea were sequentially extracted with solvents of increasing polarity to yield the hexane, ethyl acetate, ethanol and aqueous extracts. In vitro analysis revealed the ability of the extracts to scavenge 1,1-diphenyl-2-picryl-hydrazyl (DPPH), nitric oxide (NO) and hydroxyl radical. They also inhibited the activities of α-glucosidase, α-amylase and lipase enzymes. Gas chromatography-mass spectroscopic (GC-MS) analysis of the extracts revealed the presence of sterols, aromatics, aliphatic acids and esters. The identified compounds were molecularly docked with α-glucosidase, α-amylase and lipase enzymes. All compounds showed good binding affinities with the enzymes studied. The strongest binding affinities were observed for ß-amyrin, 4-phenylbenzophenone and lupenone for α-glucosidase, α-amylase and lipase enzymes, respectively. The data suggest antioxidant and antidiabetic potential of the different parts of B. ferruginea, with the leaves having the highest potential. These properties can be explored for development of novel anti-diabetic drugs.Communicated by Ramaswamy H. Sarma.

HIV Positivity and Referral to Treatment Following Testing of Partners and Children of PLHIV Index Patients in Public Sector Facilities in South Africa.

BACKGROUND: There is an imperative need for innovative interventions to identify people living with HIV and initiate them on antiretroviral therapy. The objective of this study was to determine the feasibility of providing index partner/child testing of people living with HIV. METHODS: We trained 86 nurses and counsellors in 56 public health facilities in 6 high HIV burden Districts in South Africa 2017 to provide index partner/child testing (tracing and testing of partners/children of people living with HIV). We collected programmatic data including index partner/child HIV positivity by age, gender, and location of testing. In subanalyses, we evaluated factors associated with identifying HIV-positive partners and children in separate models using multivariable logistic regression. RESULTS: We tested 16,033 partners and children of index patients between October 2017 and June 2018. Most of those tested were women (61%) and 20-39 years old (39%). Overall, 6.4% were 10-14 years old, 9.5% were 15-19 years, and 8% were ≥50 years. HIV positivity was 38% [95% confidence interval (CI) = 36% to 40%]. In children ages 10-14 years, 13% were HIV-infected (95% CI = 11% to 14%). In subanalyses, HIV positivity in partners was associated with their increased age [adjusted odds ratio (aOR) for increase in 5-year age category = 1.21; 95% CI = 1.04 to 1.42], female gender (aOR = 1.38; 95% CI = 1.04 to 1.82), and index partner bringing the partner in for HIV testing vs. referring the partner through the provider or recommending testing to the partner (aOR = 1.94, 95% CI = 1.43 to 2.63), adjusting for location of testing. Almost all patients diagnosed (97%) were referred to antiretroviral therapy. CONCLUSIONS: Providing index partner/child testing was feasible and we identified a very high yield when testing partners and children of index patients. Index partner and children testing should be offered to all patients living with HIV to improve case finding.