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The Protein Journal Apr 2020Cancers are a great threat to humans. In cancer therapy, surgical removal of the tumor combined with radiotherapy and chemotherapy is the most routine treatment... (Review)
Review
Cancers are a great threat to humans. In cancer therapy, surgical removal of the tumor combined with radiotherapy and chemotherapy is the most routine treatment procedure and usually the most effective. However, radiotherapy and chemotherapy drugs that kill cancer cells efficiently also kill normal cells, thus exhibiting large side effects. Cancer-targeted drugs, which aim to specifically recognize proteins or signaling pathways associated with tumor proliferation and migration, have achieved marked progress in recent years. Azurin is a copper-containing redox protein secreted by Pseudomonas aeruginosa. Azurin and its derived peptide p28 preferentially enter a variety of cancer cells and induce apoptosis or cell cycle arrest. Mechanistic studies revealed that azurin and p28 target the p53 and receptor tyrosine kinase signaling pathways as well as other pathways. Two phase I trials of p28 have been carried out, with findings that p28 is safe and exhibits anticancer activity in both adult and pediatric patients. In this review paper, we provide an up-to-date summary of progress on the anticancer mechanisms and therapeutic strategies for azurin and p28.
Topics: Animals; Antineoplastic Agents; Azurin; Cell Line, Tumor; Clinical Trials, Phase I as Topic; Humans; Neoplasms; Peptides
PubMed: 32180097
DOI: 10.1007/s10930-020-09891-3 -
Protein Science : a Publication of the... Dec 2017Azurin secreted by Pseudomonas aeruginosa is an anticancer bacteriocin, which preferentially enters human cancer cells and induces apoptosis or growth inhibition. It... (Review)
Review
Azurin secreted by Pseudomonas aeruginosa is an anticancer bacteriocin, which preferentially enters human cancer cells and induces apoptosis or growth inhibition. It turns out that azurin is a multi-target anticancer agent interfering in the p53 signaling pathway and the non-receptor tyrosine kinases signaling pathway. This suggests that azurin exerts its anticancer activity by interacting with multiple targets and interfering in multiple steps in disease progression. Therefore, azurin could overcome resistance to therapy. Besides azurin, putative bacteriocins that possess functional properties similar to those of azurin have been identified in more bacteria species. A systematic investigation on the anticancer mechanisms of azurin and the azurin-like bacteriocins will provide more and better options in cancer therapy. In this review, we summarize how azurin and the derived peptides hijack key cellular regulators or cell surface receptors to remodel the cellular signaling networks. In particular, we highlight the necessity of determining the structure of azurin/p53 complex and investigating the influence of post-translational modifications on interactions between azurin and p53. Therapeutic applications of azurin and derived peptides are also discussed.
Topics: Animals; Antineoplastic Agents; Azurin; Bacterial Proteins; Cell Line, Tumor; Humans; MCF-7 Cells; Mice; Protein Processing, Post-Translational; Pseudomonas aeruginosa; Signal Transduction; Tumor Suppressor Protein p53
PubMed: 28960574
DOI: 10.1002/pro.3310 -
Journal of Gastrointestinal Cancer Sep 2022To discover new natural effective anticancer agents and new antibacterial agents against antibiotic-resistant bacteria which are the most serious public health concern....
OBJECTIVES
To discover new natural effective anticancer agents and new antibacterial agents against antibiotic-resistant bacteria which are the most serious public health concern. Another important concern is drug delivery which is the transport of pharmaceutical compounds to have a therapeutic effect in organisms having a disease. Azurin is a promising anticancer agent produced from Pseudomonas aeruginosa. This study tried to test the effectiveness of the immobilization of azurin on nano-chitosan to enhance its anticancer and antibacterial activity against gastrointestinal cancer and its related bacteria.
METHODS
We purified azurin protein from Pseudomonas aeruginosa and then immobilized it on nano-chitosan. The anticancer activity of the free and nano-azurin is tested against a gastric cancer cell line (CLS-145), pancreatic cancer cell line (AsPC-1), colon cancer cell line (HCT116), esophagus cancer cell line (KYSE-410), and liver cancer cell line (HepG2). The antibacterial activity of both free and immobilized azurin also is tested against bacterial species related to the gastrointestinal cancer biopsies: Helicobacter pylori, Bacteroides fragilis, Salmonella enterica, Fusobacterium nucleatum, and Porphyromonas gingivalis.
RESULTS
Both free and nano-azurin showed high anticancer and antibacterial activity. Immobilization significantly increased the anticancer and antibacterial activity of the azurin CONCLUSION: Nano-azurin can be used as an effective anticancer and antibacterial agent against gastrointestinal cancer and bacterial species related to these cancers.
Topics: Anti-Bacterial Agents; Antineoplastic Agents; Azurin; Bacteria; Chitosan; Gastrointestinal Neoplasms; Humans; Pseudomonas aeruginosa
PubMed: 34159520
DOI: 10.1007/s12029-021-00654-6 -
ACS Biomaterials Science & Engineering Oct 2021As a potential anticancer agent, azurin has attracted extensive attraction among chemists, physicists, and material scientists. Its structural and unfolding/folding...
As a potential anticancer agent, azurin has attracted extensive attraction among chemists, physicists, and material scientists. Its structural and unfolding/folding information has been partially understood, but some detailed information, such as the difference in the unfolding processes between apo-azurin and holo-azurin, the mechanical stability, and the role of the copper cluster in its stability, has not been addressed adequately, especially at the single-molecule level. Here, we employed AFM-based single-molecule force spectroscopy to investigate the unfolding process of azurin in the apo and holo forms under an external force. The results indicated that the unfolding processes of apo-azurin and holo-azurin are different, and holo-azurin requires a stronger force to unfold than does apo-azurin. The copper cluster exhibited a more significant impact on the stability and the folding process of holo-azurin: the copper cluster was completely broken, and the copper ion left the unfolded azurin during the unfolding process of azurin. We suspected that the presence of the disulfide bond in azurin made the unfolding of the copper cluster different from that in pseudoazurin, which is also a type I copper protein like azurin. Rarely reported in previous studies, the mechanical strength of the Cu-N(His) bond of the copper cluster was obtained in this study, which is weaker than that of most metal-S(Cys) bonds but higher than that of the Fe-N(His) bond. Altogether, our results offer a possible new scenario for azurin to widely extend its anticancer activity.
Topics: Azurin; Copper; Metals; Protein Folding
PubMed: 34558912
DOI: 10.1021/acsbiomaterials.1c00934 -
Biochemical and Biophysical Research... Dec 2003
Review
Topics: Animals; Antineoplastic Agents; Apoptosis; Azurin; Coenzymes; Humans; Neoplasms; Probiotics; Protein Binding; Pseudomonas aeruginosa; Tumor Suppressor Protein p53; Tumor Suppressor Proteins
PubMed: 14630027
DOI: 10.1016/j.bbrc.2003.09.217 -
Biochemical and Biophysical Research... Jul 2021Proteins with hetero-bimetallic metal centers can catalyze important reactions and are challenging to design. Azurin is a mononuclear copper center that has been...
Proteins with hetero-bimetallic metal centers can catalyze important reactions and are challenging to design. Azurin is a mononuclear copper center that has been extensively studied for electron transfer. Here we inserted the lanthanide binding tag (LBT), which binds lanthanide with sub μM affinity, into the copper binding loop of azurin, while keeping the type 1 copper center unperturbed. The resulting protein, Az-LBT, which has two metal bonding centers, shows strong luminescence upon coordination with Tb and luminescence quenching upon Cu binding. The in vitro luminescence quenching has high metal specificity and a limit-of-detection of 0.65 μM for Cu. With the low background from lanthanide's long luminescence lifetime, bacterial cells expressing Az-LBT in the periplasm also shows sensitivity for metal sensing.
Topics: Azurin; Bacteria; Binding Sites; Biosensing Techniques; Catalysis; Copper; Lanthanoid Series Elements; Luminescence; Models, Molecular; Protein Domains
PubMed: 34004515
DOI: 10.1016/j.bbrc.2021.05.013 -
Journal of Biological Inorganic... May 2010Cu(A) is a binuclear copper center that functions as an electron transfer agent, cycling between a reduced Cu(I)Cu(I) state and an oxidized mixed-valence... (Review)
Review
Cu(A) is a binuclear copper center that functions as an electron transfer agent, cycling between a reduced Cu(I)Cu(I) state and an oxidized mixed-valence Cu(+1.5)...Cu(+1.5) state. The copper ions are bridged by two cysteine thiolate ligands and form a copper-copper bond, the first reported of its kind in Nature. Such a "diamond-core" Cu(2)S(Cys)(2) structure allows an unpaired electron to be completely delocalized over the two copper ions and contributes to its highly efficient electron transfer properties. This review provides accounts of how the Cu(A) center was structurally characterized and highlights its salient spectroscopic properties. In the process, it introduces the Cu(A) center in four different systems-native protein systems, soluble protein truncates of native proteins, synthetic models using organic molecules, and biosynthetic models using proteins as ligands-with a greater emphasis on biosynthetic models of Cu(A), especially on new, deeper insights gained from their studies.
Topics: Azurin; Copper; Spectrum Analysis
PubMed: 20169379
DOI: 10.1007/s00775-010-0625-2 -
Journal of Biological Inorganic... Dec 2023Circular permutation (CP) is a technique by which the primary sequence of a protein is rearranged to create new termini. The connectivity of the protein is altered but...
Circular permutation (CP) is a technique by which the primary sequence of a protein is rearranged to create new termini. The connectivity of the protein is altered but the overall protein structure generally remains unperturbed. Understanding the effect of CP can help design robust proteins for numerous applications such as in genetic engineering, optoelectronics, and improving catalytic activity. Studies on different protein topologies showed that CP usually affects protein stability as well as unfolding rates. Though a significant number of proteins contain metals or other cofactors, reports of metalloprotein CPs are rare. Thus, we chose a bacterial metalloprotein, azurin, and its CP within the metal-binding site (cpF114). We studied the stabilities, folding, and unfolding rates of apo- and Zn-bound CP azurin using fluorescence and circular dichroism. The introduced CP had destabilizing effects on the protein. Also, the folding of the Zn-CP protein was much slower than that of the Zn-WT or apo-protein. We compared this study to our previously reported azurin-cpN42, where we had observed an equilibrium and kinetic intermediate. cpF114 exhibits an apparent two-state equilibrium unfolding but has an off-pathway kinetic intermediate. Our study hinted at CP as a method to modify the energy landscape of proteins to alter their folding pathways. WT azurin, being a faster folder, may have evolved to optimize the folding rate of metal-bound protein compared to its CPs, albeit all of them have the same structure and function. Our study underscores that protein sequence and protein termini positions are crucial for metalloproteins. TOC Figure. (Top) Zn-azurin WT structure (PDB code: 1E67) and 2-D topology diagram of Zn-cpF114 azurin. (Bottom) Cartoon diagram representing folding (red arrows) and unfolding (blue arrows) of apo- and Zn- WT and cpF114 azurins. The width of the arrows represents the rate of the corresponding processes.
Topics: Azurin; Protein Folding; Catalytic Domain; Apoproteins; Metals; Circular Dichroism; Kinetics
PubMed: 37957357
DOI: 10.1007/s00775-023-02023-z -
Bioprocess and Biosystems Engineering Mar 2022Azurin which is a bacterial secondary metabolite has attracted much attention as potential anticancer agent in recent years. This copper-containing periplasmic redox...
Azurin which is a bacterial secondary metabolite has attracted much attention as potential anticancer agent in recent years. This copper-containing periplasmic redox protein supresses the tumor growth selectively. High-level secretion of proteins into the culture medium offers a significant advantage over periplasmic or cytoplasmic expression. The aim of this study was to investigate the effect of nonionic surfactants on the expression of the Pseudomonas aeruginosa azurin. Different concentrations of Triton X-100 and Tween 80 were used as supplements in growth media and extracellular azurin production was stimulated by both surfactants. According to western blot analysis results, in the presence of Triton X-100, maximum azurin expression level was achieved with 96 h of incubation at 1% concentration, and 48 h at 2% concentration. On the other hand, maximum azurin expression level was achieved in the presence of 1% Tween 80 at 72 h incubation. This study suggested for the first time a high level of azurin secretion from P. aeruginosa in the presence of Triton X-100 or Tween 80, which would be advantageous for the purification procedure.
Topics: Azurin; Bacterial Proteins; Copper; Octoxynol; Polysorbates; Pseudomonas aeruginosa
PubMed: 35039942
DOI: 10.1007/s00449-021-02678-5 -
Preparative Biochemistry & Biotechnology 2021Azurin, which is a bacterial secondary metabolite has been attracted as a potential anticancer agent in recent years because induced death of cancer cells and inhibited...
Azurin, which is a bacterial secondary metabolite has been attracted as a potential anticancer agent in recent years because induced death of cancer cells and inhibited their growth. In this study, the production of azurin under the control of the alcohol oxidase promoter which is frequently used in the expression system was performed. The azurin gene amplified from genomic DNA and inserted into the pPICZαA was cloned in cells. Then, a linearized recombinant vector was transferred to the X-33 cells. Antibiotic resistance test and colony PCR were performed for the selection of multicopy transformants. Protein expression capacities of selected transformants were compared at the end of 48 h incubation. Both extracellular and intracellular protein expressions were observed in all of them by Western blot analysis. The relative expression levels of both intracellular and extracellular protein that belongs to the first clone were higher than the others. On the other hand, it was seen that the 4th clone had the highest protein secretion ability. The molecular mass of the extracellular azurin protein which is produced by recombinant clones was found to be about 20 kDa. This is the first report on azurin expression in .
Topics: Azurin; Gene Expression; Pseudomonas aeruginosa; Recombinant Proteins; Saccharomycetales
PubMed: 33346686
DOI: 10.1080/10826068.2020.1855444