Nattokinase: Structure, applications and sources

Nattokinase (NK) as a serine protease enzyme has a strong fibrinolytic activity that is found in bacteria. In comparison to other fibrinolytic enzymes (plasmin, urokinase, and t-PA), NK has the advantages of a long lifespan, low cost, and no side effects. As a food supplement, it could be utilized as a substance to treat cardiovascular disease. As a result, NK has high commercial value and therapeutic applications. The current study provides a brief description of the properties of this important enzyme. Also, some of the most notable applications of NK are discussed. Eventually, different microbial, plant and animal sources of this enzyme are summarized in the last par

LYZ2-SH3b as a novel and efficient enzybiotic against methicillin-resistant Staphylococcus aureus

Abstract Background Enzybiotics are promising alternatives to conventional antibiotics for drug-resistant infections. Exolysins, as a class of enzybiotics, show antibacterial effects against methicillin-resistant Staphylococcus aureus (MRSA). This study evaluated a novel exolysin containing an SH3b domain for its antibacterial activity against MRSA. Methods This study designed a chimeric exolysin by fusing the Cell-binding domain (SH3b) from Lysostaphin with the lytic domain (LYZ2) from the gp61 enzyme. Subsequently, LYZ2-SH3b was cloned and expressed in Escherichia coli (E. coli). Finally, the antibacterial effects of LYZ2-SH3b compared with LYZ2 and vancomycin against reference and clinical isolates of MRSA were measured using the disc diffusion method, the minimal inhibitory concentration (MIC), and the minimal bactericidal concentration (MBC) assays. Results Analysis of bioinformatics showed that LYZ2-SH3b was stable, soluble, and non-allergenic. Protein purification was performed with a 0.8 mg/ml yield for LYZ2-SH3b. The plate lysis assay results indicated that, at the same concentrations, LYZ2-SH3b has a more inhibitory effect than LYZ2. The MICs of LYZ2 were 4 µg/mL (ATCC 43,300) and 8 µg/mL (clinical isolate ST239), whereas, for LYZ2-SH3b, they were 2 µg/mL (ATCC 43,300) and 4 µg/mL (clinical isolate ST239). This suggests a higher efficiency of LYZ2-SH3b compared to LYZ2. Furthermore, the MBCs of LYZ2 were 4 µg/mL (ATCC 43,300) and 8 µg/mL (clinical isolate ST239), whereas, for LYZ2-SH3b, they were 2 µg/mL (ATCC 43,300) and 4 µg/mL (clinical isolate ST239), thus confirming the superior lytic activity of LYZ2-SH3b over LYZ2. Conclusions The study suggests that phage endolysins, such as LYZ2-SH3b, may represent a promising new approach to treating MRSA infections, particularly in cases where antibiotic resistance is a concern. But further studies are needed

Exosomal microRNAs and long noncoding RNAs: Novel mediators of drug resistance in lung cancer

Lung cancer therapeutic resistance, especially chemoresistance, is a key issue in the management of this malignancy. Despite the development of novel molecularly targeted drugs to promote therapeutic efficacy, 5-year survival of lung cancer patients is still dismal. Molecular studies through the recent years have fortunately presented multiple genes and signaling pathways, which contribute to lung cancer chemoresistance, providing a better perception of the biology of tumor cells, as well as the molecular mechanisms involved in their resistance to chemotherapeutic agents. Among those mechanisms, transfer of extracellular vesicles, such as exosomes, between cancer cells and the surrounding noncancerous ones is considered as an emerging route. Exosomes can desirably function as signaling vesicles to transmit multiple molecules from normal cells to cancer cells and their microenvironment, or vice versa. Using this ability, exosomes may affect the cancer cells' chemoresistance/chemosensitivity. Recently, noncoding RNAs (esp. microRNAs and long noncoding RNAs), as key molecules transferred by exosomes, have been reported to play a substantial role in the process of drug resistance, through modulation of various proteins and their corresponding genes. Accordingly, the current review principally aims to highlight exosomal micro- and long noncoding RNAs involved in lung cancer chemoresistance. Moreover, major molecular mechanisms, which connect corresponding RNA molecules to drug resistance, will briefly be addressed, for better clarifying of possible roles of exosomal noncoding RNAs in promoting the effectiveness of lung cancer therapy

Liposomal delivery system/adjuvant for tuberculosis vaccine

Abstract As reported by the World Health Organization, about 10 million individuals were infected with tuberculosis (TB) worldwide. Moreover, approximately 1.5 million people died of TB, of which 214,000 were infected with HIV simultaneously. Due to the high infection rate, the need for effective TB vaccination is highly felt. Until now, various methodologies have been proposed for the development of a protein subunit vaccine for TB. These vaccines have shown higher protection than other vaccines, particularly the Bacillus culture vaccine. The delivery system and safety regulator are common characteristics of effective adjuvants in TB vaccines and the clinical trial stage. The present study investigates the current state of TB adjuvant research focusing on the liposomal adjuvant system. Based on our findings, the liposomal system is a safe and efficient adjuvant from nanosize to microsize for vaccinations against TB, other intracellular infections, and malignancies. Clinical studies can provide valuable feedback for developing novel TB adjuvants, which ultimately enhance the impact of adjuvants on next‐generation TB vaccines

Glucose oxidase: Applications, sources, and recombinant production

Glucose oxidase is a subset of oxidoreductase enzymes that catalyzes the transfer of electrons from an oxidant to a reductant. Glucose oxidases use oxygen as an external electron acceptor that releases hydrogen peroxide (H2O2). Glucose oxidase has many applications in commercial processes, including improving the color and taste, increasing the persistence of food materials, removing the glucose from the dried egg, and eliminating the oxygen from different juices and beverages. Moreover, glucose oxidase, along with catalase, is used in glucose testing kits (especially in biosensors) to detect and measure the presence of glucose in industrial and biological solutions (e.g., blood and urine specimens). Hence, glucose oxidase is a valuable enzyme in the industry and medical diagnostics. Therefore, evaluating the structure and function of glucose oxidase is crucial for modifying as well as improving its catalytic properties. Finding different sources of glucose oxidase is an effective way to find the type of enzyme with the desired catalysis. Besides, the recombinant production of glucose oxidase is the best approach to produce sufficient amounts of glucose oxidase for various uses. Accordingly, the study of various aspects of glucose oxidase in biotechnology and bioprocessing is crucial

Insights into the Function of Regulatory RNAs in Bacteria and Archaea

Non-coding RNAs (ncRNAs) are functional RNA molecules that comprise about 80% of both mammals and prokaryotes genomes. Recent studies have identified a large number of small regulatory RNAs in Escherichia coli and other bacteria. In prokaryotes, RNA regulators are a diverse group of molecules that modulate a wide range of physiological responses through a variety of mechanisms. Similar to eukaryotes, bacterial microRNAs are an important class of ncRNAs that play an important role in the development and secretion of proteins and in the regulation of gene expression. Similarly, riboswitches are cis-regulatory structured RNA elements capable of directly controlling the expression of downstream genes in response to small molecule ligands. As a result, riboswitches detect and respond to the availability of various metabolic changes within cells. The most extensive and most widely studied set of small RNA regulators act through base pairing with RNAs. These types of RNAs are vital for prokaryotic life, activating or suppressing important physiological processes by modifying transcription or translation. The majority of these small RNAs control responses to changes in environmental conditions. Finally, clustered regularly interspaced short palindromic repeat (CRISPR) RNAs, a newly discovered RNA regulator group, contains short regions of homology to bacteriophage and plasmid sequences that bacteria use to splice phage DNA as a defense mechanism. The detailed mechanism is still unknown but devoted to target homologous foreign DNAs. Here, we review the known mechanisms and roles of non-coding regulatory RNAs, with particular attention to riboswitches and their functions, briefly introducing translational applications of CRISPR RNAs in mammals

Exosomal lncRNAs in gastrointestinal cancer

Gastrointestinal cancer (GIC) remains a leading cause of morbidity and mortality worldwide. Unfortunately, these cancers are diagnosed in advanced metastatic stages due to lack of reliable biomarkers that are sufficiently specific and sensitive in early disease. There has been growing evidence that circulating exosomes can be used to diagnose cancer non-invasively with limited risks and side effects. Furthermore, exosomal long non-coding RNAs (lncRNAs) are emerging as a new class of promising biomarkers in cancer. This review provides an overview of the extraction and detection of exosomal lncRNAs with a focus on their potential role in GI

Designing a Humanized Immunotoxin Based on HER2 Specific scFv and DFF40 Toxin Against Breast Cancer: An In-Silico Study

Breast cancer is the most frequent cancer in women worldwide. Human epidermal growth factor receptor 2 (HER2) is a receptor which is overexpressed in breast cancer cells. Targeting this receptor could be a key factor for treatment of breast cancer patients. Herceptin is an antibody which can bind to HER2 receptor, in addition Herceptin derived single chain fragment V (scFv) can be used in designing immunotoxin for targeting HER2 positive cancer cells. DFF40 is a nuclease activated by caspase-3 and responsible for genomic DNA fragmentation during apoptosis. In this study, we used bioinformatics tools to design an immunotoxin containing HER2 specific scFv and DFF40 toxin. An immunotoxin construct was designed by linking scFv and DFF40 amino acids sequence via a peptide linker. The secondary structure, physicochemical features, solubility, and allergenicity of construct were predicted. The tertiary structure was built, refined, and evaluated. Protein-protein docking, and molecular dynamics studies were carried out for evaluation of immunotoxin-receptor binding, and the stability of the immunotoxin, respectively. The results indicated that the designed construct could be a stable protein with appropriate solubility, which is not an allergen and has a suitable structure which can bind to HER2 appropriately. Finally, this construct could be a promising candidate for producing an HER2 targeting immunotoxin. However, different in vitro and in vivo immunological assays should be performed to confirm the efficacy of the designed construct