Picosecond Time-Resolved Fluorescence: Application To The Study Of Conformational Changes Of Excited States In Solutions Of Organic Compounds

1988 ◽  
Author(s):  
Claude Rulliere ◽  
Eric Gilabert ◽  
Alain Declemy
Keyword(s):  
Organic Compounds ◽  
Excited States ◽  
Conformational Changes ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Intrinsic fluorescence as a probe of structure-function relationships in Ca2+-transport ATPases

1996 ◽  
Vol 16 (2) ◽  
pp. 87-106 ◽  
Author(s):  
Sérgio T. Ferreira ◽  
Tatiana Coelho-Sampaio
Keyword(s):  
Structure Function ◽  
Conformational Changes ◽  
Fluorescence Emission ◽  
Intrinsic Fluorescence ◽  
Future Prospects ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Fluorescence Measurements ◽  
Transport Atpases ◽  
Functional States

Applications of intrinsic fluorescence measurements in the study of Ca2+-transport ATPases are reviewed. Since the initial reports showing that the fluorescence emission was sensitive to Ca2+ binding, a substantial amount of work has focused on the use of both steady-state and time-resolved fluorescence spectroscopy to investigate structure-function relationships in sarcoplasmic reticulum and plasma membrane Ca2+-ATPases. These studies have revealed ligand-induced conformational changes, as well as provided information on protein-protein, protein-solvent and/or protein-lipid interactions in different functional states of these proteins. The main results of these studies, as well as possible future prospects are discussed.

scholarly journals Tracking Local Conformational Changes of Ribonuclease A Using Picosecond Time-Resolved Fluorescence of the Six Tyrosine Residues

2007 ◽  
Vol 92 (12) ◽  
pp. 4401-4414 ◽  
Author(s):  
Melinda Noronha ◽  
João C. Lima ◽  
Emanuele Paci ◽  
Helena Santos ◽  
António L. Maçanita
Keyword(s):  
Conformational Changes ◽  
Ribonuclease A ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Tyrosine Residues

Cation Effect on the Electronic Excited States of Guanine Nanostructures Studied by Time-Resolved Fluorescence Spectroscopy

2012 ◽  
Vol 116 (27) ◽  
pp. 14682-14689 ◽  
Author(s):  
Ying Hua ◽  
Pascale Changenet-Barret ◽  
Roberto Improta ◽  
Ignacio Vayá ◽  
Thomas Gustavsson ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Excited States ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Electronic Excited States ◽  
Cation Effect

scholarly journals Sequestration Effect on the Open-Cyclic Switchable Property of Warfarin by Cyclodextrin: Ultrafast Dynamical Study

2017 ◽  
Author(s):  
Naji Al-Dubaili ◽  
Na'il Saleh
Keyword(s):  
Excited State ◽  
Excited States ◽  
Time Resolved Fluorescence ◽  
Excited State Lifetime ◽  
Deprotonated Form ◽  
Dynamical Study ◽  
Visible Absorption ◽  
Time Resolved ◽  
Pka Values ◽  
Fluorescence Measurements

The excited-state lifetimes of the anticoagulant drug warfarin (W) in water and in the absence and presence of methyl-β-cyclodextrins (Me-β-CD) were recorded using time-resolved fluorescence measurements. Selective excitation of the open and cyclic protonated isomers of W were acquired with laser emitting diodes (LED) producing 320 and 280 nm excitation pulses, respectively. Formation of the inclusion complex was checked by UV–visible absorption spectroscopy, and the values of binding constants (2.9 × 103 M–1 and 4.2 × 102 M–1 for protonated and deprotonated forms, respectively) were extracted from the spectrophotometric data. Both absorption and time-resolved fluorescence results established that the interior of the macromolecular host binds preferentially the open protonated form, red shifts the maximum of its absorption of light at ~305 nm, extends its excited-state lifetime, and decreases its emission quantum yield (ФF). Collectively, sequestration of the open guest molecules decreases markedly their radiative rate constants (kr), likely due to formation of hydrogen-bonded complexes in both the ground and excited states. Due to lack of interactions, no change was observed in the excited-state lifetime of the cyclic form in the presence of Me-β-CD. The host also increases the excited-state lifetime and ФF of the drug deprotonated form (W¯). These later findings could be attributed to the increased rigidity inside the cavity of Me-β-CD. The pKa values extracted from the variations of the UV–visible absorption spectra of W versus the pH of aqueous solution showed that the open isomer is more acidic in both ground and excited states. The positive shifts in pKa values induced by three derivatives of cyclodextrins: HE-β-CD, Ac-β-CD, and Me-β-CD supported the preferential binding of these hosts to open isomers over cyclic.

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