Search

Background: Cholera triggered by Vibrio cholerae remains the main reason for morbidity and mortality all over the world. In addition, salmonellosis is regarded as an infectious disease that makes it essential for the identification and detection of Salmonella. With a beta-barrel structure consisting of eight non-parallel beta strands, OmpW family is widely distributed among gram-negative bacteria. Moreover, OmpW isolated from S. typhimurium and Vibrio cholerae can be used in vaccine design. Methods: Topology prediction was determined. T-cell and B-cell epitopes were selected from exposed areas, and sequence conservancy was evaluated. The remaining loops and inaccessible residues were removed to prepare OmpW-1. High antigenicity peptides were detected to replace inappropriate residues to obtain OmpW-2. Physicochemical properties were assessed, and antigenicity, hydrophobicity, flexibility, and accessibility were compared to the native Omp-W structure. Low score areas were removed from the designed structure for preparing the OmpW-3. To construct OmpW-4, TTFrC was used as T-CD4+ cell-stimulating factor and CTB as adjuvant to the end of the C-terminal of this sequence, which can increase the antigenicity and sequence density. The sequences were re-analyzed to delete the unfavorable residues. Besides, the solubility of the mature OmpW and the designed structure were predicted while overexpressed in E. coli. Results: The designed vaccine is a stable protein which has immune cells recognizing epitopes and is considered as an antigen. The construct can be overexpressed in a E. coli. Conclusion: The multi-epitope vaccine is a suitable stimulator for immune system and would be a candidate for experimental research. Recent patents describing numerous inventions related to the clinical facets of vaccine peptide against human infectious disease.

Background: Methotrexate (MTX) is a general chemotherapeutic agent utilized to treat a variety of malignancies, woefully, its high doses can cause nephrotoxicity and subsequent defect in the process of MTX excretion. The recombinant form of glucarpidase is produced by engineered E. coli and is a confirmed choice to overcoming this problem. Objective: In the present study, in silico analyses were performed to select suitable SPs for the secretion of recombinant glucarpidase in E. coli. Methods: The signal peptide website and UniProt database were employed to collect the SPs and protein sequences. In the next step, SignalP-5.0 helped us to predict the SPs and the position of cleavage sites. Moreover, physicochemical properties and solubility were evaluated using Prot- Param and Protein-sol online software, and finally, ProtCompB was used to predict the final subcellular localization. Results: Luckily, all SPs could form soluble fusion proteins. At last, it was found that PPB and TIBA could translocate the glucarpidase into the extracellular compartment. Conclusion: This study showed that there are only 2 applicable SPs for the extracellular translocation of glucarpidase. Although the findings were remarkable with high degrees of accuracy and precision based on the utilization of bioinformatics analyses, additional experimental assessments are required to confirm and validate it. Recent patents revealed several inventions related to the clinical aspects of vaccine peptides against human disorders.

To enhance the thermal stability of Streptomyces Sp. SA-COO cholesterol oxidase, random mutagenesis was used. A random mutant library was generated using two types of error-prone PCR (single step and serial dilution) and two mutants (ChOA-M1 and ChOA-M2) with improved thermostability were obtained. The best mutant ChOA-M1 acquired three amino acid substitutions (G49T, W52K, and F62V) and improved thermostability (at 50 °C for 5 h) by 40% and increased the kcat/Km value by 23%. The optimum pH was desirably changed to encompass a broad range from alkali to acid and circular dichroism revealed no significant secondary structure changes in mutants against wild type. These findings indicated that random mutagenesis was an effective technique for optimizing cholesterol oxidase properties and make a foundation for practical applications of Cholesterol oxidase in clinical diagnosis and industrial fields.