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Alternative Therapies in Health and... Oct 2023Osteosarcoma (OS) is the most common bone malignancy, with a high mortality rate in adolescents. Despite advancements in therapeutic interventions, OS prognosis remains...
BACKGROUND
Osteosarcoma (OS) is the most common bone malignancy, with a high mortality rate in adolescents. Despite advancements in therapeutic interventions, OS prognosis remains poor due to drug resistance. P21, a cyclin-dependent kinase inhibitor, plays a critical role in cell cycle regulation and has been implicated in OS pathogenesis. Cisplatin (DDP) is a conventional chemotherapeutic agent for OS, but its efficacy is often limited due to drug resistance. Azurin, a bacterial redox protein, has been reported to exhibit antitumor activity. However, its interaction with P21 in OS remains unexplored. In this study, we sought to investigate the impact of azurin on the cytotoxic effect of DDP against OS cells in relation to P21 expression.
METHODS
Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to determine the level of p21 and apoptosis-related factors in U2OS cells. A Cell Counting Kit-8 (CCK-8) was used to examine the effects of azurin-p21 on the U2OS cell proliferation rate. Flow cytometry (FCM)was used to analyze the impact of azurin-P21 on the apoptosis/cell cycle. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the effects of azurin-P21 on the secretion of oxygen free radicals, glutathione and glutathione peroxidase.
RESULTS
Azurin exhibited significant cytotoxic activity against U2OS cells expressing wild-type (WT) P21, with minimal impact on SAOS-2 and MG63 cells lacking endogenous P21. Azurin treatment resulted in increased expression of procaspase-3 and Bax, decreased expression of B-cell lymphoma-2 (Bcl-2) and a consequential increase in apoptosis. The depletion of P21 attenuated these effects, suggesting the crucial role of P21 in azurin-mediated cytotoxicity. Furthermore, azurin synergistically enhanced the cytotoxic effect of DDP against U2OS cells, which was mitigated by P21 depletion.
CONCLUSIONS
Our findings demonstrated that azurin selectively induces apoptosis and cell cycle arrest in U2OS cells, which is mediated via P21. This study highlights the potential of azurin as a sensitizer for DDP in the treatment of OS. Future studies on DDP-resistant OS cells may further elucidate the clinical relevance of our findings.
PubMed: 37442187
DOI: No ID Found -
Journal of the American Chemical Society Sep 2023Much progress has been made in understanding the roles of the secondary coordination sphere (SCS) in tuning redox potentials of metalloproteins. In contrast, the impact...
Much progress has been made in understanding the roles of the secondary coordination sphere (SCS) in tuning redox potentials of metalloproteins. In contrast, the impact of SCS on reactivity is much less understood. A primary example is how copper proteins can promote -nitrosylation (SNO), which is one of the most important dynamic post-translational modifications, and is crucial in regulating nitric oxide storage and transportation. Specifically, the factors that instill Cu with -nitrosylating capabilities and modulate activity are not well understood. To address this issue, we investigated the influence of the primary and secondary coordination sphere on Cu-catalyzed -nitrosylation by developing a series of azurin variants with varying catalytic capabilities. We have employed a multidimensional approach involving electronic absorption, S and Cu K-edge XAS, EPR, and resonance Raman spectroscopies together with QM/MM computational analysis to examine the relationships between structure and molecular mechanism in this reaction. Our findings have revealed that kinetic competency is correlated with three balancing factors, namely Cu-S bond strength, Cu spin localization, and relative S(p) vs S(p) contributions to the ground state. Together, these results support a reaction pathway that proceeds through the attack of the Cu-S bond rather than electrophilic addition to Cu or radical attack of S. The insights gained from this work provide not only a deeper understanding of SNO in biology but also a basis for designing artificial and tunable SNO enzymes to regulate NO and prevent diseases due to SNO dysregulation.
Topics: Azurin; Copper; Metalloproteins; Catalysis; Electronics
PubMed: 37696009
DOI: 10.1021/jacs.3c07399 -
The Journal of Physical Chemistry... Dec 2023We conducted a theoretical study of electron transport through junctions of the blue-copper azurin from . We found that single-site hopping can lead to either higher or...
We conducted a theoretical study of electron transport through junctions of the blue-copper azurin from . We found that single-site hopping can lead to either higher or lower current values compared to fully coherent transport. This depends on the structural details of the junctions as well as the alignment of the protein orbitals. Moreover, we show how the asymmetry of the curves can be affected by the position of the tip in the junction and that, under specific conditions, such a hopping mechanism is consistent with a fairly low temperature dependence of the current. Finally, we show that increasing the number of hopping sites leads to higher hopping currents. Our findings, from fully quantum calculations, provide deep insight to help guide the interpretation of experimental curves on highly complex systems.
PubMed: 38059566
DOI: 10.1021/acs.jpclett.3c02702 -
Cell Reports. Medicine May 2024Bacteria-based therapies are powerful strategies for cancer therapy, yet their clinical application is limited by a lack of tunable genetic switches to safely regulate...
Bacteria-based therapies are powerful strategies for cancer therapy, yet their clinical application is limited by a lack of tunable genetic switches to safely regulate the local expression and release of therapeutic cargoes. Rapid advances in remote-control technologies have enabled precise control of biological processes in time and space. We developed therapeutically active engineered bacteria mediated by a sono-activatable integrated gene circuit based on the thermosensitive transcriptional repressor TlpA. Through promoter engineering and ribosome binding site screening, we achieved ultrasound (US)-induced protein expression and secretion in engineered bacteria with minimal noise and high induction efficiency. Specifically, delivered either intratumorally or intravenously, engineered bacteria colonizing tumors suppressed tumor growth through US-irradiation-induced release of the apoptotic protein azurin and an immune checkpoint inhibitor, a nanobody targeting programmed death-ligand 1, in different tumor mouse models. Beyond developing safe and high-performance designer bacteria for tumor therapy, our study illustrates a sonogenetics-controlled therapeutic platform that can be harnessed for bacteria-based precision medicine.
Topics: Animals; Mice; Humans; Neoplasms; Disease Models, Animal; Cell Line, Tumor; Female; B7-H1 Antigen; Immune Checkpoint Inhibitors; Escherichia coli
PubMed: 38608697
DOI: 10.1016/j.xcrm.2024.101513 -
Pharmaceutics Jun 2023Azurin is a natural protein produced by that exhibits potential anti-tumor, anti-HIV, and anti-parasitic properties. The current study aimed to investigate the...
Azurin is a natural protein produced by that exhibits potential anti-tumor, anti-HIV, and anti-parasitic properties. The current study aimed to investigate the potential of azurin protein against breast cancer using both in silico and in vitro analyses. The amino acid sequence of Azurin was used to predict its secondary and tertiary structures, along with its physicochemical properties, using online software. The resulting structure was validated and confirmed using Ramachandran plots and ERRAT2. The mature azurin protein comprises 128 amino acids, and the top-ranked structure obtained from I-TASSER was shown to have a molecular weight of 14 kDa and a quality factor of 100% by ERRAT2, with 87.4% of residues in the favored region of the Ramachandran plot. Docking and simulation studies of azurin protein were conducted using HDOCK and Desmond servers, respectively. The resulting analysis revealed that Azurin docked against p53 and EphB2 receptors demonstrated maximum binding affinity, indicating its potential to cause apoptosis. The recombinant azurin gene was successfully cloned and expressed in a BL21 (DE3) strain using a pET20b expression vector under the control of the pelB ladder, followed by IPTG induction. The azurin protein was purified to high levels using affinity chromatography, yielding 70 mg/L. In vitro cytotoxicity assay was performed using MCF-7 cells, revealing the significant cytotoxicity of the azurin protein to be 105 µg/mL. These findings highlight the potential of azurin protein as an anticancer drug candidate.
PubMed: 37514012
DOI: 10.3390/pharmaceutics15071825 -
Bioengineering (Basel, Switzerland) Oct 2023Compared to chemical drugs, therapeutic proteins exhibit higher specificity and activity and are generally well-tolerated by the human body. However, the limitations,...
Compared to chemical drugs, therapeutic proteins exhibit higher specificity and activity and are generally well-tolerated by the human body. However, the limitations, such as poor stability both in vivo and in vitro as well as difficulties in penetrating cell membranes, hinder their widespread application. To overcome the challenges, a highly efficient protocol was developed and implemented for the recombinant expression of the therapeutic protein azurin and secretion into minicells derived from probiotic Nissle 1917. The novel coupled production with a delivery system of therapeutic proteins based on minicells was obtained through purification to enhance protein activity, circulation characteristics, and targeting specificity. This protein drug carrier integrates the production of carrier materials and the loading of expression proteins. The drug carrier also protects the encapsulated polypeptide drugs from enzymatic or gastric acid degradation until they are released. Nissle 1917-derived minicells have natural targeting to colon cancer cells, low toxicity, and can accumulate for a long time after penetrating tumor tissue. This self-produced protein drug delivery system simplified the process of protein preparation, and its inhibitory effect on different types of colon cancer cells was verified by CCK-8 cytotoxicity assay, cancer cell invasion, and migration assay. This work provided a simple method to prepare minicell drug delivery systems for protein drug production and a novel approach for the transport of recombinant protein drugs.
PubMed: 37892918
DOI: 10.3390/bioengineering10101188 -
Infection, Genetics and Evolution :... Aug 2023Gonorrhea is an urgent antimicrobial resistance threat and its therapeutic options are continuously getting restricted. Moreover, no vaccine has been approved against it...
Reverse vaccinology approaches to introduce promising immunogenic and drug targets against antibiotic-resistant Neisseria gonorrhoeae: Thinking outside the box in current prevention and treatment.
Gonorrhea is an urgent antimicrobial resistance threat and its therapeutic options are continuously getting restricted. Moreover, no vaccine has been approved against it so far. Hence, the present study aimed to introduce novel immunogenic and drug targets against antibiotic-resistant Neisseria gonorrhoeae strains. In the first step, the core proteins of 79 complete genomes of N. gonorrhoeae were retrieved. Next, the surface-exposed proteins were evaluated from different aspects such as antigenicity, allergenicity, conservancy, and B-cell and T-cell epitopes to introduce promising immunogenic candidates. Then, the interactions with human Toll-like receptors (TLR-1, 2, and 4), and immunoreactivity to elicit humoral and cellular immune responses were simulated. On the other hand, to identify novel broad-spectrum drug targets, the cytoplasmic and essential proteins were detected. Then, the N. gonorrhoeae metabolome-specific proteins were compared to the drug targets of the DrugBank, and novel drug targets were retrieved. Finally, the protein data bank (PDB) file availability and prevalence among the ESKAPE group and common sexually transmitted infection (STI) agents were assessed. Our analyses resulted in the recognition of ten novel and putative immunogenic targets including murein transglycosylase A, PBP1A, Opa, NlpD, Azurin, MtrE, RmpM, LptD, NspA, and TamA. Moreover, four potential and broad-spectrum drug targets were identified including UMP kinase, GlyQ, HU family DNA-binding protein, and IF-1. Some of the shortlisted immunogenic and drug targets have confirmed roles in adhesion, immune evasion, and antibiotic resistance that can induce bactericidal antibodies. Other immunogenic and drug targets might be associated with the virulence of N. gonorrhoeae as well. Thus, further experimental studies and site-directed mutations are recommended to investigate the role of potential vaccine and drug targets in the pathogenesis of N. gonorrhoeae. It seems that the efforts for proposing novel vaccines and drug targets appear to be paving the way for a prevention-treatment strategy against this bacterium. Additionally, a combination of bactericidal monoclonal antibodies and antibiotics is a promising approach to curing N. gonorrhoeae.
Topics: Humans; Neisseria gonorrhoeae; Anti-Bacterial Agents; Vaccinology; Gonorrhea; Membrane Proteins
PubMed: 37225067
DOI: 10.1016/j.meegid.2023.105449 -
Chemical Science May 2024Native chemical ligation (NCL) has been playing an increasingly important role in chemical protein synthesis (CPS). More efficient ligation methods that circumvent the...
Native chemical ligation (NCL) has been playing an increasingly important role in chemical protein synthesis (CPS). More efficient ligation methods that circumvent the requirement of a peptidyl thioester and thiol additive-which allow the following desulfurization or refolding in one pot-are urgently needed for the synthesis of more complex protein targets and in large quantities. Herein, we discover that the weak acyl donor peptidyl -acyl pyrazole can be activated by azole reagents like 3-methylpyrazole or imidazole to facilitate its ligation directly with an N-terminal cysteine peptide. As it requires no thioester or thiol additive, this ligation strategy can be conveniently combined with metal-free desulfurization (MFD) or oxidative protein folding to allow various one-pot protocols. The utility and generality of the strategy are showcased by the total synthesis of ubiquitin an N-to-C sequential ligation-MFD strategy, the semi-synthesis of the copper protein azurin, and the efficient assembly of a sulfated hirudin variant and the cyclotide kalata B1, all in a one-pot fashion.
PubMed: 38817582
DOI: 10.1039/d3sc06697e -
Marine Drugs Jan 2024Biofilm is accountable for nosocomial infections and chronic illness, making it a serious economic and public health problem. , thanks to its ability to form biofilm and...
Biofilm is accountable for nosocomial infections and chronic illness, making it a serious economic and public health problem. , thanks to its ability to form biofilm and colonize biomaterials, represents the most frequent causative agent involved in biofilm-associated infections of medical devices. Therefore, the research of new molecules able to interfere with biofilm formation has a remarkable interest. In the present work, the attention was focused on sp. TAE6080, an Antarctic marine bacterium able to produce and secrete an effective antibiofilm compound. The molecule responsible for this activity was purified by an activity-guided approach and identified by LC-MS/MS. Results indicated the active protein was a periplasmic protein similar to the PAO1 azurin, named cold-azurin. The cold-azurin was recombinantly produced in and purified. The recombinant protein was able to impair attachment to the polystyrene surface and effectively prevent biofilm formation.
Topics: Pseudomonas; Azurin; Anti-Bacterial Agents; Antarctic Regions; Escherichia coli; Chromatography, Liquid; Tandem Mass Spectrometry; Biofilms; Pseudomonas aeruginosa; Staphylococcus epidermidis
PubMed: 38393032
DOI: 10.3390/md22020061 -
Journal of Inorganic Biochemistry Jul 2024Motivated by the ambition to establish an enzyme-driven bioleaching pathway for copper extraction, properties of the Type-1 copper protein rusticyanin from...
Kinetic, electrochemical and spectral characterization of bacterial and archaeal rusticyanins; unexpected stability issues and consequences for applications in biotechnology.
Motivated by the ambition to establish an enzyme-driven bioleaching pathway for copper extraction, properties of the Type-1 copper protein rusticyanin from Acidithiobacillus ferrooxidans (AfR) were compared with those from an ancestral form of this enzyme (N0) and an archaeal enzyme identified in Ferroplasma acidiphilum (FaR). While both N0 and FaR show redox potentials similar to that of AfR their electron transport rates were significantly slower. The lack of a correlation between the redox potentials and electron transfer rates indicates that AfR and its associated electron transfer chain evolved to specifically facilitate the efficient conversion of the energy of iron oxidation to ATP formation. In F. acidiphilum this pathway is not as efficient unless it is up-regulated by an as of yet unknown mechanism. In addition, while the electrochemical properties of AfR were consistent with previous data, previously unreported behavior was found leading to a form that is associated with a partially unfolded form of the protein. The cyclic voltammetry (CV) response of AfR immobilized onto an electrode showed limited stability, which may be connected to the presence of the partially unfolded state of this protein. Insights gained in this study may thus inform the engineering of optimized rusticyanin variants for bioleaching processes as well as enzyme-catalyzed solubilization of copper-containing ores such as chalcopyrite.
Topics: Kinetics; Electrochemistry; Azurin; Actinobacteria; Thermoplasmales; Electron Spin Resonance Spectroscopy; Models, Molecular; Protein Structure, Tertiary; Iron; Oxidation-Reduction; Biotechnology; Protein Stability; Conserved Sequence
PubMed: 38593609
DOI: 10.1016/j.jinorgbio.2024.112539