Electron Transfer Towards the RCI-Type Photosystem in the Green Sulphur Bacterium Chlorobium limicola Forma Thiosulphatophilum Studied by Time-Resolved Optical Spectroscopy In Vivo

1997 ◽  
Vol 249 (2) ◽  
pp. 630-636 ◽  
Author(s):  
Delphine Albouy ◽  
Pierre Joliot ◽  
Bruno Robert ◽  
Wolfgang Nitschke
Keyword(s):  
Electron Transfer ◽  
Optical Spectroscopy ◽  
Chlorobium Limicola ◽  
Time Resolved ◽  
Green Sulphur Bacterium ◽  
Green Sulphur

scholarly journals New combination chemotherapy of cisplatin with an electron-donating compound for treatment of multiple cancers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qinrong Zhang ◽  
Qing-Bin Lu
Keyword(s):  
Electron Transfer ◽  
Side Effects ◽  
Transfer Mechanism ◽  
New Combination ◽  
Dissociative Electron Transfer ◽  
Time Resolved ◽  
Electron Transfer Mechanism ◽  
Platinum Based Chemotherapy

AbstractCisplatin is the first and most widely used platinum-based chemotherapy drug and is the cornerstone agent in treating a broad spectrum of cancers. However, its clinical application is often limited by severe toxic side effects and drug resistance. Based on the discovered dissociative electron transfer mechanism of cisplatin, a novel combination of cisplatin with [9-(2-carboxyphenyl)-6-diethylamino-3-xanthenylidene]-diethylammonium chloride (basic violet 10, BV10) is proposed to potentiate the chemotherapeutic effect of cisplatin. Here, we show that this combination enhances the anti-cancer effect of cisplatin in both in vitro cell lines and in vivo xenograft mouse models of cisplatin-sensitive and -resistant lung, ovarian and cervical cancers while introducing minimal additional toxic side effects. Furthermore, femtosecond time-resolved laser spectroscopic measurements demonstrate that cisplatin reacts with BV10 via an electron transfer mechanism. These results indicate that the combination of cisplatin with BV10 is promising for improving the chemotherapy of cancers with various extents of cisplatin resistance.

Interfacial Electron Transfer in MoS2 Nanoclusters

1999 ◽  
Vol 571 ◽  
Author(s):  
F. Parsapour ◽  
D.F. Kelley
Keyword(s):  
Electron Transfer ◽  
Optical Spectroscopy ◽  
Photoinduced Electron Transfer ◽  
Electron Acceptors ◽  
Kinetics Model ◽  
Interfacial Electron Transfer ◽  
Electron Hole ◽  
Time Resolved ◽  
Recombination Kinetics ◽  
Hole Recombination

ABSTRACTThe dynamics of photoinduced electron transfer between 3.0 nm diameter MoS2 nanoclusters and adsorbed electron acceptors have been studied using static and time resolved optical spectroscopy. Two types of electron acceptors are adsorbed on these nanoclusters: 2,2'-bipyridine and 4,4',5,5'-tetramethyl-2,2'-bipyridine. The results reported here focus on the interpretation of the strongly non-exponential electron transfer kinetics. Electron/hole recombination kinetics have previously been analyzed in terms of a simple distributed kinetics model, and this model is extended to include the case of interfacial electron transfer.

In vivo time-resolved optical spectroscopy of mice

2002 ◽  
Author(s):  
E.E. Graves ◽  
A. Petrovsky ◽  
R. Weissleder ◽  
V. Ntziachristos
Keyword(s):  
Optical Spectroscopy ◽  
Time Resolved

scholarly journals Real-time observation of tetrapyrrole binding to an engineered bacterial phytochrome

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yusaku Hontani ◽  
Mikhail Baloban ◽  
Francisco Velazquez Escobar ◽  
Swetta A. Jansen ◽  
Daria M. Shcherbakova ◽  
...  
Keyword(s):  
Real Time ◽  
Rational Design ◽  
Near Infrared ◽  
Fluorescent Proteins ◽  
Covalent Bond ◽  
Binding Pocket ◽  
Tissue Imaging ◽  
Covalent Attachment ◽  
Time Resolved

AbstractNear-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes are widely used for structural and functional deep-tissue imaging in vivo. To fluoresce, NIR FPs covalently bind a chromophore, such as biliverdin IXa tetrapyrrole. The efficiency of biliverdin binding directly affects the fluorescence properties, rendering understanding of its molecular mechanism of major importance. miRFP proteins constitute a family of bright monomeric NIR FPs that comprise a Per-ARNT-Sim (PAS) and cGMP-specific phosphodiesterases - Adenylyl cyclases - FhlA (GAF) domain. Here, we structurally analyze biliverdin binding to miRFPs in real time using time-resolved stimulated Raman spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. Biliverdin undergoes isomerization, localization to its binding pocket, and pyrrolenine nitrogen protonation in <1 min, followed by hydrogen bond rearrangement in ~2 min. The covalent attachment to a cysteine in the GAF domain was detected in 4.3 min and 19 min in miRFP670 and its C20A mutant, respectively. In miRFP670, a second C–S covalent bond formation to a cysteine in the PAS domain occurred in 14 min, providing a rigid tetrapyrrole structure with high brightness. Our findings provide insights for the rational design of NIR FPs and a novel method to assess cofactor binding to light-sensitive proteins.

scholarly journals Influence of Oxidative Stress on Time-Resolved Oxygen Detection by [Ru(Phen)3]2+ In Vivo and In Vitro

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 485
Author(s):  
Veronika Huntosova ◽  
Denis Horvath ◽  
Robert Seliga ◽  
Georges Wagnieres
Keyword(s):  
Oxidative Stress ◽  
Tissue Oxygenation ◽  
Intact Cell ◽  
Molecular Probes ◽  
Stress Factors ◽  
Time Resolved ◽  
Invasive Approach ◽  
Oxygen Detection

Detection of tissue and cell oxygenation is of high importance in fundamental biological and in many medical applications, particularly for monitoring dysfunction in the early stages of cancer. Measurements of the luminescence lifetimes of molecular probes offer a very promising and non-invasive approach to estimate tissue and cell oxygenation in vivo and in vitro. We optimized the evaluation of oxygen detection in vivo by [Ru(Phen)3]2+ in the chicken embryo chorioallantoic membrane model. Its luminescence lifetimes measured in the CAM were analyzed through hierarchical clustering. The detection of the tissue oxygenation at the oxidative stress conditions is still challenging. We applied simultaneous time-resolved recording of the mitochondrial probe MitoTrackerTM OrangeCMTMRos fluorescence and [Ru(Phen)3]2+ phosphorescence imaging in the intact cell without affecting the sensitivities of these molecular probes. [Ru(Phen)3]2+ was demonstrated to be suitable for in vitro detection of oxygen under various stress factors that mimic oxidative stress: other molecular sensors, H2O2, and curcumin-mediated photodynamic therapy in glioma cancer cells. Low phototoxicities of the molecular probes were finally observed. Our study offers a high potential for the application and generalization of tissue oxygenation as an innovative approach based on the similarities between interdependent biological influences. It is particularly suitable for therapeutic approaches targeting metabolic alterations as well as oxygen, glucose, or lipid deprivation.

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