scholarly journals Two-Dimensional Fluorescence Lifetime Correlation Spectroscopy: Concepts and Applications

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2972 ◽  
Author(s):  
Takuhiro Otosu ◽  
Shoichi Yamaguchi
Keyword(s):  
Single Molecule ◽  
Fluorescence Lifetime ◽  
Fluorescence Correlation Spectroscopy ◽  
Conformational Dynamics ◽  
Correlation Spectroscopy ◽  
Two Dimensional ◽  
Single Molecule Level ◽  
Fluorescence Correlation ◽  
Promising Tool ◽  
Molecular Ruler

We review the basic concepts and recent applications of two-dimensional fluorescence lifetime correlation spectroscopy (2D FLCS), which is the extension of fluorescence correlation spectroscopy (FCS) to analyze the correlation of fluorescence lifetime in addition to fluorescence intensity. Fluorescence lifetime is sensitive to the microenvironment and can be a “molecular ruler” when combined with FRET. Utilization of fluorescence lifetime in 2D FLCS thus enables us to quantify the inhomogeneity of the system and the interconversion dynamics among different species with a higher time resolution than other single-molecule techniques. Recent applications of 2D FLCS to various biological systems demonstrate that 2D FLCS is a unique and promising tool to quantitatively analyze the microsecond conformational dynamics of macromolecules at the single-molecule level.

Characterization of Pteridines: a New Approach by Fluorescence Correlation Spectroscopy and Analysis of Assay Sensitivity

Pteridines ◽  
2001 ◽  
Vol 12 (4) ◽  
pp. 147-153 ◽  
Author(s):  
U. Demel ◽  
Z. Foldes-Papp ◽  
D. Fuchs ◽  
G. P. Tilz
Keyword(s):  
Single Molecule ◽  
Fluorescence Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Cell Mediated Immunity ◽  
Distribution Analysis ◽  
Assay Sensitivity ◽  
New Approach ◽  
Single Molecule Level ◽  
Fluorescence Correlation

Abstract In the present investigation, fluorescence con-elation spectroscopy (FCS) was used to measure the molecular motion of the pteridine derivative neopterin. However, technical limitations in the present optical setup precluded the identification of ,single neopterin molecules. FCS measurements with a fluorophore were also can-ied out for comparison. Exemplified by rhodamine green, we have introduced a concept that allows the detection, identification and analysis of assays in solution at the single-molecule level in tenns of bulk concentration. This concept is based on FCS and Poisson distribution analysis of assay sensitivity. The molecules had not to be quantified in a more concentrated fonn, or in flow and trapping experiments. The study demonstrated an ultrasensitive, reliable, rapid and direct tool for analytics and diagnostics in solution. We discuss a possible application of our new concept in activation control of cell-mediated immunity via neopterin determination.

scholarly journals FRET at the Single Molecule Level using Molecular Brightness and Fluorescence Correlation Spectroscopy

2019 ◽  
Vol 116 (3) ◽  
pp. 567a ◽  
Author(s):  
Robert C. Miller ◽  
Rowan Simonet ◽  
Christin Libal ◽  
Cody Aplin ◽  
Anh Cong ◽  
...  
Keyword(s):  
Single Molecule ◽  
Fluorescence Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Single Molecule Level ◽  
Fluorescence Correlation ◽  
Molecular Brightness

scholarly journals Stoichiometric Analysis of Protein Complexes by Cell Fusion and Single Molecule Imaging

2020 ◽  
Author(s):  
Avtar Singh ◽  
Alexander L. Van Slyke ◽  
Maria Sirenko ◽  
Alexander Song ◽  
Paul J. Kammermeier ◽  
...  
Keyword(s):  
Single Molecule ◽  
Fluorescence Correlation Spectroscopy ◽  
Protein Complexes ◽  
Correlation Spectroscopy ◽  
Single Molecule Fluorescence ◽  
Single Molecule Level ◽  
Fluorescence Correlation ◽  
Cellular Environment ◽  
Low Expression

ABSTRACTThe composition, stoichiometry and interactions of supramolecular protein complexes are a critical determinant of biological function. Several techniques have been developed to study molecular interactions and quantify subunit stoichiometry at the single molecule level; however, these typically require artificially low expression levels to achieve the low fluorophore concentration required for single molecule imaging, or use of detergent isolation of complexes that may perturb native subunit interactions. Here we present an alternative approach where protein complexes are assembled at physiological concentrations and subsequently diluted in situ for single-molecule level observations while preserving them in a near-native cellular environment. We show that coupling this in situ dilution strategy with single molecule techniques such as in vivo Fluorescence Correlation Spectroscopy (FCS), bleach step counting for quantifying protein complex stoichiometry, and two-color single molecule colocalization, improves the quality of data obtained using these single molecule fluorescence methods. Single Protein Recovery After Dilution (SPReAD) is a simple and versatile means of extending the concentration range of single molecule measurements into the cellular regime while minimizing potential artifacts and perturbations of protein complex stoichiometry.SIGNIFICANCE STATEMENTQuantifying the composition and stoichiometry of protein complexes in live cells is critical to understanding mechanisms involved in their function. Here we detail a method in which protein complexes are assembled intracellularly at physiological concentrations, but then diluted to levels suitable for single-molecule fluorescence observations while still within a cellular environment. The technique permits the use of common single molecule analysis techniques such as stepwise photobleaching quantification and fluorescence correlation spectroscopy to determine stoichiometry and functional interactions while avoiding artifacts that may occur from the use of detergent isolation methods or from the artificially low expression levels sometimes used to attain single molecule observation levels.

Fluorescence correlation spectroscopy at single molecule level on the Tat–TAR complex and its inhibitors

Biopolymers ◽  
2008 ◽  
Vol 89 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Chayan Kanti Nandi ◽  
Partha Pratim Parui ◽  
Bernhard Brutschy ◽  
Ute Scheffer ◽  
Michael Göbel
Keyword(s):  
Single Molecule ◽  
Fluorescence Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Single Molecule Level ◽  
Fluorescence Correlation
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