The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Konstantin A. Lukyanov - One of the best experts on this subject based on the ideXlab platform.
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targeting cancer cells by using an antireceptor antibody Photosensitizer fusion protein
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Ekaterina O Serebrovskaya, Konstantin A. Lukyanov, Dmitriy M. Chudakov, E F Edelweiss, Oleg A Stremovskiy, S M DeyevAbstract:Antibody-Photosensitizer chemical conjugates are used successfully to kill cancer cells in photodynamic therapy. However, chemical conjugation of Photosensitizers presents several limitations, such as poor reproducibility, aggregation, and free Photosensitizer impurities. Here, we report a fully genetically encoded immunoPhotosensitizer, consisting of a specific anti-p185HER-2-ECD antibody fragment 4D5scFv fused with the phototoxic fluorescent protein KillerRed. Both parts of the recombinant protein preserved their functional properties: high affinity to antigen and light activation of sensitizer. 4D5scFv-KillerRed showed fine targeting properties and efficiently killed p185HER-2-ECD-expressing cancer cells upon light irradiation. It also showed a remarkable additive effect with the commonly used antitumor agent cisplatin, further demonstrating the potential of the approach.
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A genetically encoded Photosensitizer
Nature Biotechnology, 2006Co-Authors: Maria E. Bulina, Yurii G. Yanushevich, Tatyana V. Chepurnykh, Ekaterina M. Merzlyak, Maria A. Shkrob, Olga V Britanova, Dmitriy M. Chudakov, Dmitry B. Staroverov, Sergey Lukyanov, Konstantin A. LukyanovAbstract:Photosensitizers are chromophores that generate reactive oxygen species (ROS) upon light irradiation. They are used for inactivation of specific proteins by chromophore-assisted light inactivation (CALI) and for light-induced cell killing in photodynamic therapy. Here we report a genetically encoded Photosensitizer, which we call KillerRed, developed from the hydrozoan chromoprotein anm2CP, a homolog of green fluorescent protein (GFP). KillerRed generates ROS upon irradiation with green light. Whereas known Photosensitizers must be added to living systems exogenously, KillerRed is fully genetically encoded. We demonstrate the utility of KillerRed for light-induced killing of Escherichia coli and eukaryotic cells and for inactivating fusions to beta-galactosidase and phospholipase Cdelta1 pleckstrin homology domain.
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a genetically encoded Photosensitizer
Nature Biotechnology, 2006Co-Authors: Maria E. Bulina, Yurii G. Yanushevich, Tatyana V. Chepurnykh, Ekaterina M. Merzlyak, Maria A. Shkrob, Olga V Britanova, Dmitriy M. Chudakov, Dmitry B. Staroverov, Sergey Lukyanov, Konstantin A. LukyanovAbstract:Photosensitizers are chromophores that generate reactive oxygen species (ROS) upon light irradiation1. They are used for inactivation of specific proteins by chromophore-assisted light inactivation (CALI) and for light-induced cell killing in photodynamic therapy. Here we report a genetically encoded Photosensitizer, which we call KillerRed, developed from the hydrozoan chromoprotein anm2CP, a homolog of green fluorescent protein (GFP). KillerRed generates ROS upon irradiation with green light. Whereas known Photosensitizers must be added to living systems exogenously, KillerRed is fully genetically encoded. We demonstrate the utility of KillerRed for light-induced killing of Escherichia coli and eukaryotic cells and for inactivating fusions to β-galactosidase and phospholipase Cδ1 pleckstrin homology domain.
Dmitriy M. Chudakov - One of the best experts on this subject based on the ideXlab platform.
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targeting cancer cells by using an antireceptor antibody Photosensitizer fusion protein
Proceedings of the National Academy of Sciences of the United States of America, 2009Co-Authors: Ekaterina O Serebrovskaya, Konstantin A. Lukyanov, Dmitriy M. Chudakov, E F Edelweiss, Oleg A Stremovskiy, S M DeyevAbstract:Antibody-Photosensitizer chemical conjugates are used successfully to kill cancer cells in photodynamic therapy. However, chemical conjugation of Photosensitizers presents several limitations, such as poor reproducibility, aggregation, and free Photosensitizer impurities. Here, we report a fully genetically encoded immunoPhotosensitizer, consisting of a specific anti-p185HER-2-ECD antibody fragment 4D5scFv fused with the phototoxic fluorescent protein KillerRed. Both parts of the recombinant protein preserved their functional properties: high affinity to antigen and light activation of sensitizer. 4D5scFv-KillerRed showed fine targeting properties and efficiently killed p185HER-2-ECD-expressing cancer cells upon light irradiation. It also showed a remarkable additive effect with the commonly used antitumor agent cisplatin, further demonstrating the potential of the approach.
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A genetically encoded Photosensitizer
Nature Biotechnology, 2006Co-Authors: Maria E. Bulina, Yurii G. Yanushevich, Tatyana V. Chepurnykh, Ekaterina M. Merzlyak, Maria A. Shkrob, Olga V Britanova, Dmitriy M. Chudakov, Dmitry B. Staroverov, Sergey Lukyanov, Konstantin A. LukyanovAbstract:Photosensitizers are chromophores that generate reactive oxygen species (ROS) upon light irradiation. They are used for inactivation of specific proteins by chromophore-assisted light inactivation (CALI) and for light-induced cell killing in photodynamic therapy. Here we report a genetically encoded Photosensitizer, which we call KillerRed, developed from the hydrozoan chromoprotein anm2CP, a homolog of green fluorescent protein (GFP). KillerRed generates ROS upon irradiation with green light. Whereas known Photosensitizers must be added to living systems exogenously, KillerRed is fully genetically encoded. We demonstrate the utility of KillerRed for light-induced killing of Escherichia coli and eukaryotic cells and for inactivating fusions to beta-galactosidase and phospholipase Cdelta1 pleckstrin homology domain.
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a genetically encoded Photosensitizer
Nature Biotechnology, 2006Co-Authors: Maria E. Bulina, Yurii G. Yanushevich, Tatyana V. Chepurnykh, Ekaterina M. Merzlyak, Maria A. Shkrob, Olga V Britanova, Dmitriy M. Chudakov, Dmitry B. Staroverov, Sergey Lukyanov, Konstantin A. LukyanovAbstract:Photosensitizers are chromophores that generate reactive oxygen species (ROS) upon light irradiation1. They are used for inactivation of specific proteins by chromophore-assisted light inactivation (CALI) and for light-induced cell killing in photodynamic therapy. Here we report a genetically encoded Photosensitizer, which we call KillerRed, developed from the hydrozoan chromoprotein anm2CP, a homolog of green fluorescent protein (GFP). KillerRed generates ROS upon irradiation with green light. Whereas known Photosensitizers must be added to living systems exogenously, KillerRed is fully genetically encoded. We demonstrate the utility of KillerRed for light-induced killing of Escherichia coli and eukaryotic cells and for inactivating fusions to β-galactosidase and phospholipase Cδ1 pleckstrin homology domain.
Marcel P Bruchez - One of the best experts on this subject based on the ideXlab platform.
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a genetically targetable near infrared Photosensitizer
Nature Methods, 2016Co-Authors: Jianjun He, Yi Wang, Maria A Missinato, Ezenwa O Onuoha, Lydia A Perkins, Simon C Watkins, Claudette M St Croix, Michael Tsang, Marcel P BruchezAbstract:Upon illumination, Photosensitizer molecules produce reactive oxygen species that can be used for functional manipulation of living cells, including protein inactivation, targeted-damage introduction and cellular ablation. Photosensitizers used to date have been either exogenous, resulting in delivery and removal challenges, or genetically encoded proteins that form or bind a native photosensitizing molecule, resulting in a constitutively active Photosensitizer inside the cell. We describe a genetically encoded fluorogen-activating protein (FAP) that binds a heavy atom-substituted fluorogenic dye, forming an 'on-demand' activated Photosensitizer that produces singlet oxygen and fluorescence when activated with near-infrared light. This targeted and activated Photosensitizer (TAPs) approach enables protein inactivation, targeted cell killing and rapid targeted lineage ablation in living larval and adult zebrafish. The near-infrared excitation and emission of this FAP-TAPs provides a new spectral range for Photosensitizer proteins that could be useful for imaging, manipulation and cellular ablation deep within living organisms.
Faina Nakonechny - One of the best experts on this subject based on the ideXlab platform.
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eradication of gram positive and gram negative bacteria by Photosensitizers immobilized in polystyrene
Photochemistry and Photobiology, 2013Co-Authors: Faina Nakonechny, Anna Pinkus, Ortal Yehosha, Yeshayahu Nitzan, Marina NisnevitchAbstract:Immobilization of Photosensitizers in polymers opens prospects for their continuous and reusable application. Methylene blue (MB) and Rose Bengal were immobilized in polystyrene by mixing solutions of the Photosensitizers in chloroform with a polymer solution, followed by air evaporation of the solvent. This procedure yielded 15–140 μm polymer films with a porous surface structure. The method chosen for immobilization ensured 99% enclosure of the Photosensitizer in the polymer. The antimicrobial activity of the immobilized Photosensitizers was tested against Gram-positive and Gram-negative bacteria. It was found that both immobilized Photosensitizers exhibited high antimicrobial properties, and caused by a 1.5–3 log10 reduction in the bacterial concentrations to their total eradication. The bactericidal effect of the immobilized Photosensitizers depended on the cell concentration and on the illumination conditions. Scanning electron microscopy was used to prove that immobilized Photosensitizers excited by white light caused irreversible damage to microbial cells. Photosensitizers immobilized on a solid phase can be applied for continuous disinfection of wastewater bacteria.
Andrés H. Thomas - One of the best experts on this subject based on the ideXlab platform.
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unraveling the degradation mechanism of purine nucleotides photosensitized by pterins the role of charge transfer steps
ChemPhysChem, 2015Co-Authors: Mariana P. Serrano, Carolina Lorente, Claudio Darío Borsarelli, Andrés H. ThomasAbstract:: Photosensitized reactions contribute to the development of skin cancer and are used in many applications. Photosensitizers can act through different mechanisms. It is currently accepted that if the Photosensitizer generates singlet molecular oxygen ((1) O2 ) upon irradiation, the target molecule can undergo oxidation by this reactive oxygen species and the reaction needs dissolved O2 to proceed, therefore the reaction is classified as (1) O2 -mediated oxidation (type II mechanism). However, this assumption is not always correct, and as an example, a study on the degradation of 2'-deoxyguanosine 5'-monophosphate photosensitized by pterin is presented. A general mechanism is proposed to explain how the degradation of biological targets, such as nucleotides, photosensitized by pterins, naturally occurring (1) O2 Photosensitizers, takes place through an electron-transfer-initiated process (type I mechanism), whereas the contribution of the (1) O2 -mediated oxidation is almost negligible.
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Type I Photosensitization of 2′‐deoxyadenosine 5′‐monophosphate (5′‐dAMP) by Biopterin and its Photoproduct Formylpterin
Photochemistry and Photobiology, 2013Co-Authors: Mariana P. Serrano, Claudio Darío Borsarelli, Andrés H. ThomasAbstract:Biopterin (Bip) and its photoproducts 6-formylpterin (Fop) and 6-carboxypterin (Cap) accumulate in the skin of patients suffering from vitiligo, a chronic depigmentation disorder where the protection against UV radiation fails because of the lack of melanin. These compounds absorb in the UV-A inducing a potential photosensitizing action that can cause damage to DNA and other biomolecules. In this work, we have investigated the capability of these pterin derivatives (Pt) to act as Photosensitizers under UV-A irradiation for the degradation of 2′-deoxyadenosine 5′-monophosphate (5′-dAMP) in aqueous solutions, as model DNA target. Steady-state and time-resolved experiments were performed and the effect of pH was evaluated. The results showed that photosensitized degradation of 5′-dAMP was only observed under acidic conditions, and a mechanistic analysis revealed the participation of the triplet excited state of the pterin derivatives (3Pt*) by electron transfer yielding the corresponding pair of radical ions (Pt•− and 5′-dAMP•+), with successive Photosensitizer recovery by electron transfer from Pt•− to O2. Finally, 5′-dAMP•+ participates in subsequent reactions to yield degradation products.
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Oxidation of Tyrosine Photoinduced by Pterin in Aqueous Solution
Photochemistry and Photobiology, 2013Co-Authors: Carolina Castaño, M. Laura Dántola, Andrés H. Thomas, Esther Oliveros, Carolina LorenteAbstract:Pterins, heterocyclic compounds widespread in biological systems, accumulate in the skin of patients suffering from vitiligo, a chronic depigmentation disorder. Pterins have been previously identified as good Photosensitizers under UV-A irradiation. In this work, we have investigated the ability of pterin (Ptr), the parent compound of oxidized pterins, to photosensitize the oxidation of tyrosine (Tyr) in aqueous solutions. Tyr is an important target in the study of the photodynamic effects of UV-A radiation because it is oxidized by singlet oxygen (1O2) and plays a key role in polymerization and cross-linking of proteins. Steady UV-A irradiation of solutions containing Ptr and Tyr led to the consumption of Tyr and dissolved O2, whereas the Ptr concentration remained unchanged. Concomitantly, hydrogen peroxide (H2O2) was produced. By combining different analytical techniques, we could establish that the mechanism of the photosensitized process involves an electron transfer from Tyr to the triplet excited state of Ptr. Mass spectrometry, chromatography and fluorescence were used to analyze the photoproducts. In particular, oxygenated and dimeric compounds were identified.
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Photosensitizing properties of biopterin and its photoproducts using 2′-deoxyguanosine 5′-monophosphate as an oxidizable target
Physical Chemistry Chemical Physics, 2012Co-Authors: Mariana P. Serrano, Carolina Lorente, Faustino E. Morán Vieyra, Claudio Darío Borsarelli, Andrés H. ThomasAbstract:UV-A radiation (320–400 nm) induces damage to the DNA molecule and its components through photosensitized reactions. Biopterin (Bip) and its photoproducts 6-formylpterin (Fop) and 6-carboxypterin (Cap) accumulate in the skin of human beings suffering from vitiligo, a depigmentation disorder where the protection against UV radiation fails because of the lack of melanin. This study was aimed to evaluate the photosensitizing properties of oxidized pterins present in the skin and to elucidate the mechanisms involved in the photosensitized oxidation of purine nucleotides by pterins in vitro. For this purpose, steady-state and time-resolved experiments in acidic (pH 5.0–5.8) aqueous solution were performed using Bip, Fop and Cap as Photosensitizers and the nucleotide 2′-deoxyguanosine 5′-monophosphate (dGMP) as an oxidizable target. The three pterin derivatives are able to photosensitize dGMP, being Fop the most efficient sensitizer. The reactions proceed through two competing pathways: (1) electron transfer from dGMP to triplet excited-state of pterins (type I mechanism) and (2) reaction of dGMP with 1O2 produced by pterins (type II mechanism). Kinetic analysis revealed that the electron transfer pathway is the main mechanism and the interaction of dGMP with the triplet excited-state of pterins and the formation of the corresponding dGMP radicals were demonstrated by laser flash photolysis experiments. The biological implications of the results obtained are also discussed.
