A cross-correlation spectroscopy in subterahertz region using an incoherent light source

2000 ◽  
Vol 76 (12) ◽  
pp. 1519-1521 ◽  
Author(s):  
O. Morikawa ◽  
M. Tonouchi ◽  
M. Hangyo
Keyword(s):  
Light Source ◽  
Cross Correlation ◽  
Correlation Spectroscopy ◽  
Incoherent Light

scholarly journals Fluorescence Cross-Correlation Spectroscopy Yields True Affinity and Binding Kinetics of Plasmodium Lactate Transport Inhibitors

2021 ◽  
Vol 14 (8) ◽  
pp. 757
Author(s):  
Iga Jakobowska ◽  
Frank Becker ◽  
Stefano Minguzzi ◽  
Kerrin Hansen ◽  
Björn Henke ◽  
...  
Keyword(s):  
Rate Constants ◽  
Cross Correlation ◽  
Fluorescent Protein ◽  
Correlation Spectroscopy ◽  
Confocal Imaging ◽  
Binding Kinetics ◽  
Acceptor Site ◽  
Lactate Transport ◽  
Entry Site ◽  
Hydrogen Bond Acceptor

Blocking lactate export in the parasitic protozoan Plasmodium falciparum is a novel strategy to combat malaria. We discovered small drug-like molecules that inhibit the sole plasmodial lactate transporter, PfFNT, and kill parasites in culture. The pentafluoro-3-hydroxy-pent-2-en-1-one BH296 blocks PfFNT with nanomolar efficiency but an in vitro selected PfFNT G107S mutation confers resistance against the drug. We circumvented the mutation by introducing a nitrogen atom as a hydrogen bond acceptor site into the aromatic ring of the inhibitor yielding BH267.meta. The current PfFNT inhibitor efficiency values were derived from yeast-based lactate transport assays, yet direct affinity and binding kinetics data are missing. Here, we expressed PfFNT fused with a green fluorescent protein in human embryonic kidney cells and generated fluorescent derivatives of the inhibitors, BH296 and BH267.meta. Using confocal imaging, we confirmed the location of the proposed binding site at the cytosolic transporter entry site. We then carried out fluorescence cross-correlation spectroscopy measurements to assign true Ki-values, as well as kon and koff rate constants for inhibitor binding to PfFNT wildtype and the G107S mutant. BH296 and BH267.meta gave similar rate constants for binding to PfFNT wildtype. BH296 was inactive on PfFNT G107S, whereas BH267.meta bound the mutant protein albeit with weaker affinity than to PfFNT wildtype. Eventually, using a set of PfFNT inhibitor compounds, we found a robust correlation of the results from the biophysical FCCS binding assay to inhibition data of the functional transport assay.

Dual-color fluorescence cross-correlation spectroscopy on a planar optofluidic chip

Lab on a Chip ◽  
2011 ◽  
Vol 11 (8) ◽  
pp. 1502 ◽  
Author(s):  
A. Chen ◽  
M. M. Eberle ◽  
E. J. Lunt ◽  
S. Liu ◽  
K. Leake ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Correlation Spectroscopy ◽  
Dual Color ◽  
Optofluidic Chip

scholarly journals Fluorescence Correlation and Cross-Correlation Spectroscopy Unveil Cytoplasmic mRNP Composition and Dynamics

2020 ◽  
Author(s):  
Àngels Mateu-Regué ◽  
Jan Christiansen ◽  
Christian Hellriegel ◽  
Finn Cilius Nielsen
Keyword(s):  
Life Cycle ◽  
Dynamic Analysis ◽  
Cross Correlation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Correlation Spectroscopy ◽  
Live Cells ◽  
Macromolecular Complexes ◽  
Fluorescence Correlation ◽  
Macromolecular Composition

ABSTRACTUnderstanding the mRNA life cycle requires analysis of the dynamic macromolecular composition and stoichiometry of mRNPs. Fluorescence correlation and cross-correlation spectroscopy (FCS and FCCS) are appealing technologies to study mRNP complexes because they readily provide information about the molecular composition, stoichiometry, heterogeneity and dynamics of the particles. We developed FCS protocols for analysis of live cells and cellular lysates, and demonstrate the feasibility of analysing common cytoplasmic mRNPs composed of core factor YBX1, IMPs (or IGF2BPs) and their interactions with other RNA binding proteins such as PABPC1, ELAVL2 (HuB), STAU1 and FMRP. FCCS corroborated previously reported RNA dependent interactions between the factors and provided an estimate of the relative overlap between the factors in the mRNPs. In this way FCS and FCCS provide a new and useful approach for the quantitative and dynamic analysis of mRNP macromolecular complexes that may complement current biochemical approaches.

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