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Koninti RK, Palvai S, Satpathi S, Basu S, Hazra P. Loading of an anti-cancer drug into mesoporous silica nano-channels and its subsequent release to DNA. NANOSCALE 2016; 8:18436-18445. [PMID: 27775145 DOI: 10.1039/c6nr06285g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Mesoporous silica nano-channel (MCM-41) based molecular switching of a biologically important anticancer drug, namely, ellipticine (EPT) has been utilized to probe its efficient loading onto MCM-41, and its subsequent release to intra-cellular biomolecules, like DNA. By exploiting various spectroscopic techniques (like, steady state fluorescence, time-resolved fluorescence and circular dichroism), it has been shown that EPT can be easily translocated from MCM-41 to DNA without using any external stimulant. Blue emission of EPT in a polar aprotic solvent, i.e., dichloromethane (DCM), completely switches to green upon loading inside MCM-41 due to the conversion from a neutral to a protonated form of the drug inside nano-pores. Powder X-ray diffraction (PXRD), N2 gas adsorption and confocal fluorescence microscopy results confirm the adsorption of EPT inside the nano-pores of MCM-41. Here, the lysozyme (Lyz) protein has been utilized as a pore blocker of MCM-41 in order to prevent premature drug release. Interestingly, EPT is released to DNA even from the EPT-MCM-Lyz composite system, and results in intensification of green fluorescence. Electron microscopy results reveal the formation of a distinctive garland kind of morphology involving MCM-41 and DNA probably through non-covalent interactions, and this is believed to be responsible for the DNA assisted release of drug molecules from silica nano-pores. Confocal laser scanning microscopy (CLSM) imaging revealed that EPT-MCM is successfully internalized into the HeLa cervical cancer cells and localized into the nucleus. Cell viability assay results infer that EPT-MCM and EPT-MCM-Lyz showed much improved efficacy in HeLa cancer cells compared to free ellipticine.
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Affiliation(s)
- Raj Kumar Koninti
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India.
| | - Sandeep Palvai
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India.
| | - Sagar Satpathi
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India.
| | - Sudipta Basu
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India.
| | - Partha Hazra
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune, Maharashtra, India.
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Correia M, Snabe T, Thiagarajan V, Petersen SB, Campos SRR, Baptista AM, Neves-Petersen MT. Photonic activation of plasminogen induced by low dose UVB. PLoS One 2015; 10:e0116737. [PMID: 25635856 PMCID: PMC4312030 DOI: 10.1371/journal.pone.0116737] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/12/2014] [Indexed: 11/18/2022] Open
Abstract
Activation of plasminogen to its active form plasmin is essential for several key mechanisms, including the dissolution of blood clots. Activation occurs naturally via enzymatic proteolysis. We report that activation can be achieved with 280 nm light. A 2.6 fold increase in proteolytic activity was observed after 10 min illumination of human plasminogen. Irradiance levels used are in the same order of magnitude of the UVB solar irradiance. Activation is correlated with light induced disruption of disulphide bridges upon UVB excitation of the aromatic residues and with the formation of photochemical products, e.g. dityrosine and N-formylkynurenine. Most of the protein fold is maintained after 10 min illumination since no major changes are observed in the near-UV CD spectrum. Far-UV CD shows loss of secondary structure after illumination (33.4% signal loss at 206 nm). Thermal unfolding CD studies show that plasminogen retains a native like cooperative transition at ~70 ºC after UV-illumination. We propose that UVB activation of plasminogen occurs upon photo-cleavage of a functional allosteric disulphide bond, Cys737-Cys765, located in the catalytic domain and in van der Waals contact with Trp761 (4.3 Å). Such proximity makes its disruption very likely, which may occur upon electron transfer from excited Trp761. Reduction of Cys737-Cys765 will result in likely conformational changes in the catalytic site. Molecular dynamics simulations reveal that reduction of Cys737-Cys765 in plasminogen leads to an increase of the fluctuations of loop 760–765, the S1-entrance frame located close to the active site. These fluctuations affect the range of solvent exposure of the catalytic triad, particularly of Asp646 and Ser74, which acquire an exposure profile similar to the values in plasmin. The presented photonic mechanism of plasminogen activation has the potential to be used in clinical applications, possibly together with other enzymatic treatments for the elimination of blood clots.
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Affiliation(s)
- Manuel Correia
- Department of Physics and Nanotechnology, Aalborg University, Aalborg, Denmark
| | - Torben Snabe
- Department of Physics and Nanotechnology, Aalborg University, Aalborg, Denmark
| | - Viruthachalam Thiagarajan
- BioPhotonics Group, Department of Nanomedicine, International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- School of Chemistry, Bharathidasan University, Tiruchirappalli, India
| | - Steffen Bjørn Petersen
- BioPhotonics Group, Department of Nanomedicine, International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
- The Institute for Lasers, Photonics and Biophotonics; University at Buffalo, The State University of New York, New York, United States of America
| | - Sara R. R. Campos
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - António M. Baptista
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Maria Teresa Neves-Petersen
- BioPhotonics Group, Department of Nanomedicine, International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- * E-mail:
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Xiao JM, Feng L, Zhou LS, Gao HZ, Zhang YL, Yang KW. Novel fluorescent cephalosporins: Synthesis, antimicrobial activity and photodynamic inactivation of antibiotic resistant bacteria. Eur J Med Chem 2013; 59:150-9. [DOI: 10.1016/j.ejmech.2012.11.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/24/2012] [Accepted: 11/12/2012] [Indexed: 11/29/2022]
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FLUORESCENT PROBES FOR INVESTIGATION PEPTIDE NATURE SUBSTANCES IN THE CRYOPRESERVED ORGANS FRAGMENTS EXTRACTS. BIOTECHNOLOGIA ACTA 2013. [DOI: 10.15407/biotech6.05.108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Correia M, Neves-Petersen MT, Jeppesen PB, Gregersen S, Petersen SB. UV-light exposure of insulin: pharmaceutical implications upon covalent insulin dityrosine dimerization and disulphide bond photolysis. PLoS One 2012; 7:e50733. [PMID: 23227203 PMCID: PMC3515625 DOI: 10.1371/journal.pone.0050733] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/24/2012] [Indexed: 12/11/2022] Open
Abstract
In this work we report the effects of continuous UV-light (276 nm, ~2.20 W.m(-2)) excitation of human insulin on its absorption and fluorescence properties, structure and functionality. Continuous UV-excitation of the peptide hormone in solution leads to the progressive formation of tyrosine photo-product dityrosine, formed upon tyrosine radical cross-linkage. Absorbance, fluorescence emission and excitation data confirm dityrosine formation, leading to covalent insulin dimerization. Furthermore, UV-excitation of insulin induces disulphide bridge breakage. Near- and far-UV-CD spectroscopy shows that UV-excitation of insulin induces secondary and tertiary structure losses. In native insulin, the A and B chains are held together by two disulphide bridges. Disruption of either of these bonds is likely to affect insulin's structure. The UV-light induced structural changes impair its antibody binding capability and in vitro hormonal function. After 1.5 and 3.5 h of 276 nm excitation there is a 33.7% and 62.1% decrease in concentration of insulin recognized by guinea pig anti-insulin antibodies, respectively. Glucose uptake by human skeletal muscle cells decreases 61.7% when the cells are incubated with pre UV-illuminated insulin during 1.5 h. The observations presented in this work highlight the importance of protecting insulin and other drugs from UV-light exposure, which is of outmost relevance to the pharmaceutical industry. Several drug formulations containing insulin in hexameric, dimeric and monomeric forms can be exposed to natural and artificial UV-light during their production, packaging, storage or administration phases. We can estimate that direct long-term exposure of insulin to sunlight and common light sources for indoors lighting and UV-sterilization in industries can be sufficient to induce irreversible changes to human insulin structure. Routine fluorescence and absorption measurements in laboratory experiments may also induce changes in protein structure. Structural damage includes insulin dimerization via dityrosine cross-linking or disulphide bond disruption, which affects the hormone's structure and bioactivity.
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Affiliation(s)
- Manuel Correia
- Department of Physics and Nanotechnology, Aalborg University, Aalborg, Denmark
| | - Maria Teresa Neves-Petersen
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- NanoBiotechnology Group, Department of Biotechnology, Chemistry and Environmental Sciences, Aalborg University, Aalborg, Denmark
- * E-mail:
| | - Per Bendix Jeppesen
- Aarhus University Hospital, Aarhus Sygehus THG, Department of Medicine and Endocrinology MEA, Aarhus C, Denmark
| | - Søren Gregersen
- Aarhus University Hospital, Aarhus Sygehus THG, Department of Medicine and Endocrinology MEA, Aarhus C, Denmark
| | - Steffen B. Petersen
- International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
- NanoBiotechnology Group, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
- The Institute for Lasers, Photonics and Biophotonics, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
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Neves-Petersen MT, Klitgaard S, Skovsen E, Petersen SB, Tømmeraas K, Schwach-Abdellaoui K. Biophysical properties of phenyl succinic acid derivatised hyaluronic acid. J Fluoresc 2009; 20:483-92. [PMID: 19943094 DOI: 10.1007/s10895-009-0570-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Accepted: 11/05/2009] [Indexed: 11/25/2022]
Abstract
Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored with ps resolved streak camera technology. Structural and fluorescence properties changes induced on HA-PheSA due to the presence of singlet oxygen were monitored using static light scattering (SLS), steady state fluorescence and ps time resolved fluorescence studies. SLS studies provided insight into the depolymerisation kinetics of PheSA derivatised HA matrix in the presence of singlet oxygen. Time resolved fluorescence studies grave insight into the dynamics of the reaction mechanisms induced on HA-PheSA by singlet oxygen. These studies provided insight into the medical relevance of PheSA derivatised HA: its capacity of scavenging singlet oxygen and of quenching PheSA fluorescence. These studies revealed that HA-PheSA is a strong quencher of electronic excited state PheSA and acts as a scavenger of singlet oxygen, thus medical applications of this derivatised form of HA may protect tissues and organs, such as skin, against reactive oxygen species damage.
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Affiliation(s)
- Maria Teresa Neves-Petersen
- NanoBiotechnology Group, Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4A, Aalborg, Denmark.
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Boehm K, Guddorf J, Albers A, Kamiyama T, Fetzner S, Hinz HJ. Thermodynamic analysis of denaturant-induced unfolding of HodC69S protein supports a three-state mechanism. Biochemistry 2008; 47:7116-26. [PMID: 18549245 DOI: 10.1021/bi800554v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Thermodynamic stability parameters and the equilibrium unfolding mechanism of His 6HodC69S, a mutant of 1 H-3-hydroxy-4-oxoquinaldine 2,4-dioxygenase (Hod) having a Cys to Ser exchange at position 69 and an N-terminal hexahistidine tag (His 6HodC69S), have been derived from isothermal unfolding studies using guanidine hydrochloride (GdnHCl) or urea as denaturants. The conformational changes were monitored by following changes in circular dichroism (CD), fluorescence, and dynamic light scattering (DLS), and the resulting transition curves were analyzed on the basis of a sequential three-state model N = I = D. The structural changes have been correlated to catalytic activity, and the contribution to stability of the disulfide bond between residues C37 and C184 in the native protein has been established. A prominent result of the present study is the finding that, independent of the method used for denaturing the protein, the unfolding mechanism always comprises three states which can be characterized by, within error limits, identical sets of thermodynamic parameters. Apparent deviations from three-state unfolding can be rationalized by the inability of a spectroscopic probe to discriminate clearly between native, intermediate, and unfolded ensembles. This was the case for the CD-monitored urea unfolding curve.
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Affiliation(s)
- Kristian Boehm
- Institut für Physikalische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 30, 48149 Münster, Germany
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Neves-Petersen MT, Klitgaard S, Carvalho ASL, Petersen SB, Aires de Barros MR, Pinho e Melo E. Photophysics and photochemistry of horseradish peroxidase A2 upon ultraviolet illumination. Biophys J 2006; 92:2016-27. [PMID: 17189303 PMCID: PMC1861803 DOI: 10.1529/biophysj.106.095455] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Detailed analysis of the effects of ultraviolet (UV) and blue light illumination of horseradish peroxidase A2, a heme-containing enzyme that reduces H(2)O(2) to oxidize organic and inorganic compounds, is presented. The effects of increasing illumination time on the protein's enzymatic activity, Reinheitzahl value, fluorescence emission, fluorescence lifetime distribution, fluorescence mean lifetime, and heme absorption are reported. UV illumination leads to an exponential decay of the enzyme activity followed by changes in heme group absorption. Longer UV illumination time leads to lower T(m) values as well as helical content loss. Prolonged UV illumination and heme irradiation at 403 nm has a pronounced effect on the fluorescence quantum yield correlated with changes in the prosthetic group pocket, leading to a pronounced decrease in the heme's Soret absorbance band. Analysis of the picosecond-resolved fluorescence emission of horseradish peroxidase A2 with streak camera shows that UV illumination induces an exponential change in the preexponential factors distribution associated to the protein's fluorescence lifetimes, leading to an exponential increase of the mean fluorescence lifetime. Illumination of aromatic residues and of the heme group leads to changes indicative of heme leaving the molecule and/or that photoinduced chemical changes occur in the heme moiety. Our studies bring new insight into light-induced reactions in proteins. We show how streak camera technology can be of outstanding value to follow such ultrafast processes and how streak camera data can be correlated with protein structural changes.
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Affiliation(s)
- Maria Teresa Neves-Petersen
- Department of Physics and Nanotechnology, NanoBiotechnology Section, UltrafastBioSpectroscopy Group, Aalborg University, Aalborg, Denmark.
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