51
|
Costa L, Tomé JPC, Neves MGPMS, Tomé AC, Cavaleiro JAS, Cunha A, Faustino MAF, Almeida A. Susceptibility of non-enveloped DNA- and RNA-type viruses to photodynamic inactivation. Photochem Photobiol Sci 2013; 11:1520-3. [PMID: 22911122 DOI: 10.1039/c2pp25156f] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The comparative susceptibility of DNA- and RNA-type viruses to photodynamic inactivation has not yet been clearly addressed. In this study the effect of the tricationic porphyrin Tri-Py(+)-Me-PF on the inactivation of four DNA and three RNA non-enveloped phages was compared. The results obtained show that the photodynamic efficiency varied with the phage type, the RNA-type phages being much more easily photoinactivated than the DNA-type ones.
Collapse
Affiliation(s)
- Liliana Costa
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
52
|
Costa L, Faustino MAF, Tomé JPC, Neves MGPMS, Tomé AC, Cavaleiro JAS, Cunha A, Almeida A. Involvement of type I and type II mechanisms on the photoinactivation of non-enveloped DNA and RNA bacteriophages. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2013; 120:10-6. [PMID: 23416708 DOI: 10.1016/j.jphotobiol.2013.01.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 01/07/2013] [Accepted: 01/08/2013] [Indexed: 12/20/2022]
Abstract
Microbial photodynamic inactivation (PDI), involving the use of a photosensitizer (PS), light and molecular oxygen, with the subsequent production of reactive oxygen species (ROS), has been considered a promising and effective technology for viral inactivation. Although singlet oxygen is generally accepted as the main damaging species in PDI, ROS like free radicals may also be involved in the process, inducing damages to proteins, lipids, nucleic acids and other molecular structures. In this study, the relative importance of each mechanism (type I and type II) on the photoinactivation of non-enveloped DNA (T4-like phage) and RNA (Qβ phage) viruses was evaluated. For this purpose, two cationic porphyrins (Tri-Py(+)-Me-PF and Tetra-Py(+)-Me) and four different ROS scavengers were used. The scavenging effect of sodium azide and L-histidine (singlet oxygen quenchers) and of D-mannitol and L-cysteine (free radical scavengers) was assessed by exposure of both phages (T4-like and Qβ) to each cationic porphyrin (5.0μM for T4-like phage and 0.5μM for Qβ phage) and white light (40Wm(-2)) in the presence of different concentrations of the scavengers (5, 10, 50 and 100mM). Sodium azide and L-histidine gave the best protection, reducing the phototoxic effect of Tri-Py(+)-Me-PF on T4-like phage respectively by 80% and 72% and in the presence of Tetra-Py(+)-Me by 90% and 78%. Free radical scavengers D-mannitol and L-cysteine did not significantly reduce the rate of T4-like phage photoinactivation (around 20% protection, for both PS). The sodium azide protection on Qβ phage photoinactivation, in the presence of Tri-Py(+)-Me-PF, was lower (39%) when compared with T4-like phage. D-mannitol did not exert on Qβ phage any protective effect after 90min of irradiation. The effect of the simultaneous presence of singlet oxygen and free radicals scavengers at 100mM confirmed that singlet oxygen (type II mechanism) is clearly the main ROS involved in T4-like and Qβ phages photoinactivation by these two cationic PS. As RNA-type phages are more easily photoinactivated when compared with DNA-type ones, the protection conferred by the scavengers during the PDI process is lower and this should be taken into account when the main mechanism involved in PDI of different viruses is to be studied.
Collapse
Affiliation(s)
- Liliana Costa
- Department of Biology and CESAM, University of de Aveiro, 3810-193 Aveiro, Portugal
| | | | | | | | | | | | | | | |
Collapse
|
53
|
Cao A, Tang Y, Liu Y, Yuan H, Liu L. A strategy for antimicrobial regulation based on fluorescent conjugated oligomer–DNA hybrid hydrogels. Chem Commun (Camb) 2013; 49:5574-6. [DOI: 10.1039/c3cc42397b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
54
|
Costa L, Faustino MAF, Neves MGPMS, Cunha Â, Almeida A. Photodynamic inactivation of mammalian viruses and bacteriophages. Viruses 2012; 4:1034-74. [PMID: 22852040 PMCID: PMC3407894 DOI: 10.3390/v4071034] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 06/12/2012] [Accepted: 06/13/2012] [Indexed: 11/16/2022] Open
Abstract
Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.
Collapse
Affiliation(s)
- Liliana Costa
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal; (L.C.); (A.C.)
| | - Maria Amparo F. Faustino
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal; (M.A.F.F.); (M.G.P.M.S.N.)
| | - Maria Graça P. M. S. Neves
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal; (M.A.F.F.); (M.G.P.M.S.N.)
| | - Ângela Cunha
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal; (L.C.); (A.C.)
| | - Adelaide Almeida
- Department of Biology and CESAM, University of Aveiro, 3810-193 Aveiro, Portugal; (L.C.); (A.C.)
| |
Collapse
|
55
|
Carvalho CM, Tomé JP, Faustino MA, Neves MG, Tomé AC, Cavaleiro JA, Costa L, Alves E, Oliveira A, Cunha Â, Almeida A. Antimicrobial photodynamic activity of porphyrin derivatives: potential application on medical and water disinfection. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424609000528] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this highlight an overview of the advances performed by the Aveiro group on the design and synthesis of tetrapyrrolic photosensitizers with potential photodynamic antimicrobial activity is presented.
Collapse
Affiliation(s)
- Carla M.B. Carvalho
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - João P.C. Tomé
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Maria A.F. Faustino
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Maria G.P.M.S. Neves
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Augusto C. Tomé
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - José A.S. Cavaleiro
- Department of Chemistry and QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Liliana Costa
- CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Eliana Alves
- CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Anabela Oliveira
- Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Ângela Cunha
- CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Adelaide Almeida
- CESAM and Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| |
Collapse
|
56
|
Carpenter BL, Feese E, Sadeghifar H, Argyropoulos DS, Ghiladi RA. Porphyrin-Cellulose Nanocrystals: A Photobactericidal Material that Exhibits Broad Spectrum Antimicrobial Activity†. Photochem Photobiol 2012; 88:527-36. [DOI: 10.1111/j.1751-1097.2012.01117.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
57
|
Lim ME, Lee YL, Zhang Y, Chu JJH. Photodynamic inactivation of viruses using upconversion nanoparticles. Biomaterials 2011; 33:1912-20. [PMID: 22153019 DOI: 10.1016/j.biomaterials.2011.11.033] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 11/14/2011] [Indexed: 11/17/2022]
Abstract
Photodynamic therapy (PDT) is a promising treatment modality that utilizes light of an appropriate wavelength to excite photosensitive materials called photosensitizers, which upon excitation, generate reactive oxygen species (ROS) that are cytocidal and virucidal. However, problems such as hydrophobicity of photosensitizers and limited tissue penetration ability of the current light sources impeded its promotion as a mainstay in medical technology. Here, by using near-infrared (NIR)-to-visible upconversion nanoparticles (UCNs), we demonstrate UCN-based photodynamic inactivation as a potential antiviral strategy. These UCNs are nanotransducers which not only act as carriers of photosensitizers but also active participants in PDT by transducing NIR radiation to visible emissions appropriate for excitation of the attached photosensitizers. The UCNs effectively reduced the infectious virus titers in vitro with no clear pathogenicity in murine model and increased target specificity to virus-infected cells. Hence, this is a promising antiviral approach with feasible applications in the treatments of virus-associated infections, lesions and cancers.
Collapse
Affiliation(s)
- Meng Earn Lim
- Department of Bioengineering, National University of Singapore, Singapore 117576, Singapore
| | | | | | | |
Collapse
|
58
|
Tang Y, Corbitt TS, Parthasarathy A, Zhou Z, Schanze KS, Whitten DG. Light-induced antibacterial activity of symmetrical and asymmetrical oligophenylene ethynylenes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4956-4962. [PMID: 21405044 DOI: 10.1021/la105018g] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The light-induced antibacterial activity of symmetric and asymmetric oligophenylene ethynylenes (OPEs) was investigated against Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative (Escherichia coli) bacteria. To understand the light-induced biocidal effect better, the transient absorption and triplet lifetime of OPEs were studied in methanol and water. A higher triplet lifetime was observed for OPE samples in water than in methanol. The magnitudes of the changes in optical density (ΔOD) of the S-OPE-n(H) series of symmetric oligomers are much higher than that of the asymmetric OPE-n series in water and are generally correlated with the singlet oxygen yield. It was found that the antibacterial activity against both Gram-positive and Gram-negative bacteria is size-, concentration-, and time-dependent. The light-induced antibacterial activity may result from the coordinated interactions of membrane disruption and interfacial or intracellular singlet oxygen generation, and the dominant factor is most likely the latter. The results obtained in this study will aid in the design of more efficient biocides in the future.
Collapse
Affiliation(s)
- Yanli Tang
- Center for Biomedical Engineering, Department of Chemical and Nuclear Engineering, 1 University of New Mexico, MSC01 1141, Albuquerque, New Mexico 87131-0001, USA
| | | | | | | | | | | |
Collapse
|
59
|
Katafias A, Lipińska M, Strutyński K. Alkaline hydrogen peroxide as a degradation agent of methylene blue—kinetic and mechanistic studies. REACTION KINETICS MECHANISMS AND CATALYSIS 2010. [DOI: 10.1007/s11144-010-0234-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
60
|
Yin H, Li Y, Zheng Y, Ye X, Li C, Zou Z, Zhao Y. Retraction: ANTI-HIV-1 Activities of Photodynamic Therapy Using Hematoporphyrin Monomethyl Ether. Photochem Photobiol 2010; 86:994. [DOI: 10.1111/j.1751-1097.2009.00698.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
61
|
Abstract
Biofilms have been found to be involved in a wide variety of microbial infections in the body, by one estimate 80% of all infections. Infectious processes in which biofilms have been implicated include common problems such as urinary tract infections, catheter infections, middle-ear infections, sinusitis, formation of dental plaque, gingivitis, coating contact lenses, endocarditis, infections in cystic fibrosis, and infections of permanent indwelling devices such as joint prostheses and heart valves. Bacteria living in a biofilm usually have significantly different properties from free-floating bacteria of the same species, as the dense and protected environment of the film allows them to cooperate and interact in various ways. One benefit of this environment is increased resistance to detergents and antibiotics, as the dense extracellular matrix and the outer layer of cells protect the interior of the community. In some cases antibiotic resistance can be increased 1000-fold. Also, the biofilm bacteria excrete toxins that reversibly block important processes such as translation and protecting the cell from bactericidal antibiotics that are ineffective against inactive targets. In the head and neck area, biofilms are a major etiologic factor in periodontitis, wound infections, oral candidiasis, and sinus and ear infections. For the past several decades, photodynamic treatment has been reported in the literature to be effective in eradicating various microorganisms using different photosensitizers, different wavelengths of light, and different light sources. PDT has been further studied to demonstrate its effectiveness for the eradication of both Gram-negative and Gram-positive antibiotic-resistant bacteria. This chapter will focus on the use of PDT in the treatment of antibiotic-resistant biofilms, antibiotic-resistant wound infections, and azole-resistant oral candidiasis using methylene blue-based photodynamic therapy.
Collapse
|
62
|
Zupán K, Egyeki M, Tóth K, Fekete A, Herényi L, Módos K, Csík G. Comparison of the efficiency and the specificity of DNA-bound and free cationic porphyrin in photodynamic virus inactivation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2007; 90:105-12. [PMID: 18222092 DOI: 10.1016/j.jphotobiol.2007.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 11/28/2007] [Accepted: 11/28/2007] [Indexed: 10/22/2022]
Abstract
The risk of transmitting infections by blood transfusion has been substantially reduced. However, alternative methods for inactivation of pathogens in blood and its components are needed. Application of photoactivated cationic porphyrins can offer an approach to remove non-enveloped viruses from aqueous media. Here we tested the virus inactivation capability of meso-Tetrakis(4-N-methylpyridyl)porphyrin (TMPyP) and meso-Tri-(4-N-methylpyridyl)monophenylporphyrin (TMPyMPP) in the dark and upon irradiation. T7 bacteriophage, as a surrogate on non-enveloped viruses was selected as a test system. TMPyP and TMPyMPP reduce the viability of T7 phage already in the dark, which can be explained by their selective binding to nucleic acid. Both compounds proved to be efficient photosensitizers of virus inactivation. The binding of porphyrin to phage DNA was not a prerequisite of phage photosensitization, moreover, photoinactivation was more efficiently induced by free than by DNA bound porphyrin. As optical melting studies and agarose gel electrophoresis of T7 nucleoprotein revealed, photoreactions of TMPyP and TMPyMPP affect the structural integrity of DNA and also of viral proteins, despite their selective DNA binding.
Collapse
Affiliation(s)
- Kristóf Zupán
- Institute of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.
| | | | | | | | | | | | | |
Collapse
|
63
|
Katafias A, Kita P, Wrzeszcz G, Mills A. Kinetics of the methylene blue oxidation by cerium(IV) in sulphuric acid solutions. TRANSIT METAL CHEM 2006. [DOI: 10.1007/s11243-006-0120-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
64
|
Silva EMP, Giuntini F, Faustino MAF, Tomé JPC, Neves MGPMS, Tomé AC, Silva AMS, Santana-Marques MG, Ferrer-Correia AJ, Cavaleiro JAS, Caeiro MF, Duarte RR, Tavares SAP, Pegado IN, d'Almeida B, De Matos APA, Valdeira ML. Synthesis of cationic beta-vinyl substituted meso-tetraphenylporphyrins and their in vitro activity against herpes simplex virus type 1. Bioorg Med Chem Lett 2005; 15:3333-7. [PMID: 15951174 DOI: 10.1016/j.bmcl.2005.05.044] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2005] [Revised: 05/06/2005] [Accepted: 05/11/2005] [Indexed: 10/25/2022]
Abstract
An easy route to cationic beta-vinyl substituted meso-tetraphenylporphyrin derivatives is described. Two novel compounds were tested in vitro for their antiviral photoactivity against herpes simplex virus type 1. One of these compounds exhibited a significant activity, reaching 99% of virus inactivation after 15 min of photoactivation.
Collapse
Affiliation(s)
- Eduarda M P Silva
- Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
65
|
Wilson B, Gude L, Fernández MJ, Lorente A, Grant KB. Tunable DNA Photocleavage by an Acridine−Imidazole Conjugate. Inorg Chem 2005; 44:6159-73. [PMID: 16124792 DOI: 10.1021/ic048320x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We report the synthesis and characterization of photonucleases N,N'-bis[2-[bis(1H-imidazol-4-ylmethyl)amino]ethyl]-3,6-acridinediamine (7) and N-[2-[bis(1H-imidazol-4-ylmethyl)amino]ethyl]-3,6-acridinediamine (10), consisting of a central 3,6-acridinediamine chromophore attached to 4 and 2 metal-coordinating imidazole rings, respectively. In DNA reactions employing 16 metal salts, photocleavage of pUC19 plasmid is markedly enhanced when compound 7 is irradiated in the presence of either Hg(II), Fe(III), Cd(II), Zn(II), V(V), or Pb(II) (low-intensity visible light, pH 7.0, 22 degrees C, 8-50 microM 7). We also show that DNA photocleavage by 7 can be modulated by modifying buffer type and pH. Evidence of metal complex formation is provided by EDTA experiments and by NMR and electrospray ionization mass spectral data. Sodium azide, sodium benzoate, superoxide dismutase, and catalase indicate the involvement of type I and II photochemical processes in the metal-assisted DNA photocleavage reactions. Thermal melting studies show that compound 7 increases the Tm of calf thymus DNA by 10 +/- 1 degrees C at pH 7.0 and that the Tm is further increased upon the addition of either Hg(II), Cd(II), Zn(II), or Pb(II). In the case of Fe(III) and V(V), a colorimetric assay demonstrates that compound 7 sensitizes one electron photoreduction of these metals to Fe(II) and V(IV), likely accelerating the production of type I reactive oxygen species. Our data collectively indicate that buffer, pH, Hg(II), Fe(III), Cd(II), Zn(II), V(V), Pb(II), and light can be used to "tune" DNA cleavage by compound 7 under physiologically relevant conditions. The 3,6-acridinediamine acridine orange has demonstrated great promise for use as a photosensitizer in photodynamic therapy. In view of the distribution of iron in living cells, compound 7 and other metal-binding acridine-based photonucleases should be expected to demonstrate excellent photodynamic action in vivo.
Collapse
Affiliation(s)
- Beth Wilson
- Department of Chemistry, Center for Biotechnology and Drug Design, Georgia State University, P.O. Box 4098, Atlanta, Georgia 30302-4098, USA
| | | | | | | | | |
Collapse
|
66
|
Detty MR, Gibson SL, Wagner SJ. Current clinical and preclinical photosensitizers for use in photodynamic therapy. J Med Chem 2004; 47:3897-915. [PMID: 15267226 DOI: 10.1021/jm040074b] [Citation(s) in RCA: 801] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael R Detty
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA.
| | | | | |
Collapse
|
67
|
Zupán K, Herényi L, Tóth K, Majer Z, Csík G. Binding of Cationic Porphyrin to Isolated and Encapsidated Viral DNA Analyzed by Comprehensive Spectroscopic Methods. Biochemistry 2004; 43:9151-9. [PMID: 15248772 DOI: 10.1021/bi0495477] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The complexation of tetrakis(4-N-methylpyridyl)porphyrin (TMPyP) with free and encapsidated DNA of T7 bacteriophage was investigated. To identify binding modes and relative concentrations of bound TMPyP forms, the porphyrin absorption spectra at various base pair/porphyrin ratios were analyzed. Spectral decomposition, fluorescent lifetime, and circular dichroism measurements proved the presence of two main binding types of TMPyP, e.g., external binding and intercalation both in free and in encapsidated DNA. Optical melting studies revealed that TMPyP increases the strand separation temperature of both free and native phage DNA and does not change the phase transition temperature of phage capsid proteins. From these findings we concluded that TMPyP binding does not influence the protein structure and/or the protein-DNA interaction. A combined analysis of absorption spectra and fluorescence decay curves made possible the determination of concentrations of free, externally bound, and intercalated porphyrin. As a perspective, our results facilitate a qualitative analysis of the TMPyP binding process at various experimental conditions.
Collapse
Affiliation(s)
- Kristóf Zupán
- Institute of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | | | | | | | | |
Collapse
|
68
|
Egyeki M, Turóczy G, Majer Z, Tóth K, Fekete A, Maillard P, Csík G. Photosensitized inactivation of T7 phage as surrogate of non-enveloped DNA viruses: efficiency and mechanism of action. Biochim Biophys Acta Gen Subj 2003; 1624:115-24. [PMID: 14642821 DOI: 10.1016/j.bbagen.2003.10.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We investigated the efficiency and the mechanism of action of a tetraphenyl porphyrin derivative in its photoreaction with T7 phage as surrogate of non-enveloped DNA viruses. TPFP was able to sensitize the photoinactivation of T7 phage in spite of the lack of its binding to the nucleoprotein complex. The efficiency of TPFP photosensitization was limited by the aggregation and by the photobleaching of porphyrin molecules. Addition of sodium azide or 1,3-dimethyl-2-thiourea (DMTU) to the reaction mixture moderated T7 inactivation, however, neither of them inhibited T7 inactivation completely. This result suggests that both Type I and Type II reaction play a role in the virus inactivation. Optical melting studies revealed structural changes in the protein part but not in the DNA of the photochemically treated nucleoprotein complex. Polymerase chain reaction (PCR) also failed to demonstrate any DNA damage. Circular dichroism (CD) spectra of photosensitized nucleoprotein complex indicated changes in the secondary structure of both the DNA and proteins. We suggest that damages in the protein capsid and/or loosening of protein-DNA interaction can be responsible for the photodynamic inactivation of T7 phage. The alterations in DNA secondary structure might be the result of photochemical damage in phage capsid proteins.
Collapse
Affiliation(s)
- M Egyeki
- Institute of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | | | | | | | | | | | | |
Collapse
|