39 research outputs found
Light-Induced TripletTriplet Electron Resonance Spectroscopy
We present a new technique, light-induced triplet-triplet electron resonance spectroscopy (LITTER), which measures the dipolar interaction between two photoexcited triplet states, enabling both the distance and angular distributions between the two triplet moieties to be determined on a nanometer scale. This is demonstrated for a model bis-porphyrin peptide that renders dipolar traces with strong orientation selection effects. Using simulations and density functional theory calculations, we extract distance distributions and relative orientations of the porphyrin moieties, allowing the dominant conformation of the peptide in a frozen solution to be identified. LITTER removes the requirement of current light-induced electron spin resonance pulse dipolar spectroscopy techniques to have a permanent paramagnetic moiety, becoming more suitable for in-cell applications and facilitating access to distance determination in unmodified macromolecular systems containing photoexcitable moieties. LITTER also has the potential to enable direct comparison with F枚rster resonance energy transfer and combination with microscopy inside cells
Light-induced pulsed dipolar spectroscopy and other electron spin resonance studies of photogenerated paramagnetic species
This thesis is concerned with the development of new methodologies in the field of Light-induced Pulsed Electron Spin Resonance Dipolar Spectroscopy (LiPDS), with the aim of applying them to the structural investigation of complex biological macromolecular systems with endogenous or artificially-added chromophores that can be photoexcited to form triplet states.
The orientational effects in previously reported LiPDS techniques and how to exploit them to extract additional molecular conformational information are explored in Chapter 2. The ReLaserIMD and LiDEER techniques are combined to fully characterise the relative orientation of the two spin centres in porphyrin-nitroxide model peptides, and a new two-dimensional LiPDS technique (frequency-correlated ReLaserIMD) is introduced to capture the complete orientational dependence of the dipolar interaction with a single experiment. These novel methodologies are extended to non-porphyrin chromophores.
Chapter 3 goes a step further to tackle the challenge of measuring the dipolar interaction between two photogenerated triplets, removing the need for having any permanent spin centre in LiPDS. The new Light-Induced Triplet-Triplet Electron Resonance spectroscopy (LITTER) technique is developed using bis-porphyrin model peptides and an in-depth conformational study of a spectroscopic molecular ruler is performed exploiting the orientational effects. LITTER is also compared to conventional DEER spectroscopy, showing superior results, and is applied to the structural study of a dimeric heme protein and a supramolecular porphyrin tetramer.
Chapter 4 addresses some of the limitation of the LITTER technique by using non-identical chromophores and two-colour photoexcitation in bis-labelled model peptides, improved performance and direct combination with F篓orster Resonance Energy Transfer.
This thesis constitutes an important step forward in the knowledge and development of the novel field of LiPDS, by introducing new triplet spin labels, improving existing techniques, developing new experiments and analysis methods, and combining them with other experimental tools for integrative structural biology
LITTER orientation-independent analysis scripts and metadata for manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy"
LITTER_orientation_independent_analysis.zip - Scripts and metadata for the orientational averaging and orientation-independent analysis of the LITTER data presented in the manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy", for molecules [1], [2], [3] and [4]. Experimental and computational methods are described in the METHODS section of the manuscript. DOI of the manuscript to be added after acceptance.
Contents:
> Averaged_trace - Orientational averaging of experimental LITTER traces.
- LITTER_avg.DTA - Trace resulting from the average of the traces measured at different field values, weighted by the corresponding intensities of the porphyrin triplet ESR spectrum at those field positions.
- LITTER_avg_CDA.zip - Metadata and results from the analysis of the averaged trace using Comparative Deer Analyzer in DeerAnalysis2022.
> Individual_traces - Orientation-independent analysis of individual LITTER traces by DeerAnalysis2022 and Comparative Deer Analyzer.</p
README file for data repository for manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy"
Description of the contents of the data repository for manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy". Experimental and computational methods are described in the METHODS section of the manuscript. Manuscript DOI to be added after acceptance.</p
LITTER primary data for the manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy"
LITTER_primary_data.zip - Raw and phased LITTER traces acquired at the different magnetic field values for molecules [1], [2], [3] and [4] presented in the manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy". Experimental and computational methods are described in the METHODS section of the manuscript. DOI of the manuscript to be added after acceptance.
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DEER orientation-dependent analysis scripts and metadata for the manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy"
DEER_orientation_dependent_analysis.zip - Scripts and metadata for the orientation-dependent analysis of the DEER data presented in the manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy", for molecule Cu2-[3]. Experimental and computational methods are described in the METHODS section of the manuscript. DOI of the manuscript to be added after acceptance.
Contents:
- Cu2Pval4Pcis_gframe.pdb - DFT-optimized molecular geometry, in g-frame of Cu-porphyrin.
- Cu2Pval4Pcis_gframe.m - Script to parametrize molecular conformation for orientation-dependent DEER simulation.
- Cu2Pval4Pcis_gframe_OriDEERsim.txt - Parametrized molecular conformation for orientation-dependent DEER simulation.
- Input_OriPDSsim_multispin_magnetophotoselection_looping.m - Input script for orientation-dependent DEER simulations, to complete with data from Cu2Pval4Pcis_gframe_OriDEERsim.txt and parameters used for the DEER experiment.聽
- OriPDSSim_multispin_magnetophotoselection_Pop.m, OriDEER_multispin_coordinates.m and foldoridist.m - Contain functions used in the orientation-dependent DEER simulation.
- OriDEERFitting.m - Script to fit simulated library of orientation-dependent DEER traces to the experimental form factors.
> form_factors - Dipolar traces background-corrected in DeerAnalysis, used for the fitting of the simulated library of DEER traces.
> Simulations_for_fitting - Simulated library of DEER traces based on the structural model, to be used for fitting.
> Results_fitting - Results from the fitting of the simulated library of DEER traces to the experimental form factor and scripts for post-processing.
- Results_CuPval4CuPcis_TOTALp_3971TOTALB0_5_Nfitting_50_casualN_815.mat - Results from fit, the index of the molecular conformation from the library added in each fitting iteration is stored in variable "J_store".
- plotting_form_factors_and_fits.m - Script to plot experimental and fitted form factors.
- counting_plotting_pvector_results_fitting.m - Script to post-process fit results and generate centre-to-centre distance distribution and sphere file for conformational plot.
- Cu2Pval4P_DEER_pvectors_fit.mat - Molecular conformations contributing to the best fit to the experimental form factors, as [phi,theta,r,alpha,beta,gamma], and corresponding weights.
- Cu2Pval4P_DEER_centre_centre_distance_distribution.mat - Centre-to-centre distance distribution resulting from the fit.
- CuPval4CuPcis_model_based_N100.bild - Sphere file for conformational plot.
> spin_spin_distribution
- spin_spin_distrib_all_pvectors.m - Script to generate spin-spin distance distribution from fit, taking electron spin delocalization into account.
- Cu2Pval4P_DEER_spin_spin_distance_distribution.mat - Resulting spin-spin distance distribution.
> angular_distributions
- phi_distribution.m - Script to generate angular distribution of phi values from fit (deer_phi_distribution_Cu2Pval4P.mat).
- theta_distribution.m - Script to generate angular distribution of theta values from fit (deer_phi_distribution_Pval4P.mat).
- plotting_all_angular_distributions.m - Script to compare phi and theta angular distributions obtained from DEER and LITTER for Cu2-[3] and [3], respectively.
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La dona japonesa al m贸n laboral : Evoluci贸 i perspectives de futur
Aquest treball pret茅n fer un recorregut cultural, social, pol铆tic i econ貌mic de les causes que han portat a la situaci贸 actual de la dona al Jap贸 en un context temporal que es limita en els inicis del segle XX, per貌 que posa 猫mfasi en tot all貌 que pass脿 des del final de la postguerra fins a l'actualitat. L'objectiu 茅s entendre les bases sobre les que s'edifica el paper de la dona treballadora en la societat japonesa. A partir d'aquesta base i un cop analitzats els canvis que s'estan produint a nivell econ貌mic, social i pol铆tic degut a Womenomics, s'oferir脿 una opini贸 fonamentada sobre les perspectives de futur de la dona en el m贸n laboral al Jap贸.Este trabajo pretende hacer un recorrido cultural, social, pol铆tico y econ贸mico de las causas que han llevado a la situaci贸n actual de la mujer en Jap贸n en un contexto temporal que se limita en los inicios del siglo XX, pero que pone 茅nfasis en todo lo que pas贸 desde el final de la posguerra hasta la actualidad. El objetivo es entender las bases sobre las que se edifica el papel de la mujer trabajadora en la sociedad japonesa. A partir de esta base y una vez analizados los cambios que se est谩n produciendo a nivel econ贸mico, social y pol铆tico debido a Womenomics, se ofrecer谩 una opini贸n fundamentada sobre las perspectivas de futuro de la mujer en el mundo laboral en Jap贸n.Bachelor thesis for the Humanities program on East Asia
DEER primary data for manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy"
DEER_primary_data.zip - Raw and phased DEER traces acquired at the different magnetic field values for molecule Cu2-[3] in the manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy". Experimental and computational methods are described in the METHODS section of the manuscript. DOI of the manuscript to be added after acceptance.
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LITTER orientation-dependent analysis scripts and metadata for manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy"
LITTER_orientation_dependent_analysis.zip - Scripts and metadata for the orientation-dependent analysis of the LITTER data presented in manuscript "Conformational information from orientationally selective Light-Induced Triplet鈥揟riplet Electron Resonance spectroscopy", for molecules [1], [2], [3] and [4]. Experimental and computational methods are described in the METHODS section of the manuscript. DOI of the manuscript to be added after acceptance.
Contents:
- PvalnP_optimised_Dframe.pdb - DFT-optimized molecular geometry, in ZFS-frame of porphyrin triplet.
- PvalnP_relative_orientation_Dframe.m - Script to parametrize molecular conformation for orientation-dependent LITTER simulation.
- PvalnP_OriLITTERsim.txt - Parametrized molecular conformation for orientation-dependent LITTER simulation.
- plot_model.m - Script to generate distribution of molecular conformations around the DFT-optimized structure, for orientation-dependent LITTER simulation.
- Input_OriLITTERsim_looping.m - Input script for orientation-dependent LITTER simulations, to complete with data from PvalnP_OriLITTERsim.txt and parameters used for the LITTER experiment. Requires EasySpin development version (6.0.0).聽
- OriLITTERSim_v04b_tripletpump_tripletdet.m, OriLITTER_v04b_coordinates_R_spindensity.m and foldoridist.m - Contain functions used in the orientation-dependent LITTER simulation.
- OriLITTERFitting.m - Script to fit simulated library of orientation-dependent LITTER traces to the experimental form factors.
> form_factors - Dipolar traces background-corrected in DeerAnalysis, used for the fitting of the simulated library of LITTER traces.
> Simulations_for_fitting - Simulated library of LITTER traces based on the structural model, to be used for fitting.
> Results_fitting - Results from the fitting of the simulated library of LITTER traces to the experimental form factor and scripts for post-processing.
- Results_PvalnP_TOTALp_....mat - Results from fit, the index of the molecular conformation from the library added in each fitting iteration is stored in variable "J_store".
- plotting_form_factors_and_fits.m - Script to plot experimental and fitted form factors.
- counting_plotting_pvector_results_fitting.m - Script to post-process fit results and generate centre-to-centre distance distribution and sphere file for conformational plot.
- PvalnP_LITTER_pvectors_fit.mat - Molecular conformations contributing to the best fit to the experimental form factors, as [phi,theta,r,alpha,beta,gamma], and corresponding weights.
- litter_centre_centre_distance_distribution_PvalnP.mat - Centre-to-centre distance distribution resulting from the fit.
- PvalnP_model_based.bild - Sphere file for conformational plot.
> spin_spin_distribution
- spin_spin_distrib_all_pvectors.m - Script to generate spin-spin distance distribution from fit, taking triplet spin delocalization into account.
- litter_spin_spin_distance_distribution_PvalnP.mat - Resulting spin-spin distance distribution.
> angular_distributions - (for molecule [3] only)
- phi_distribution.m - Script to generate angular distribution of phi values from fit (litter_phi_distribution_Pval4P.mat).
- theta_distribution.m - Script to generate angular distribution of theta values from fit (litter_theta_distribution_Pval4P.mat).</p
La dona japonesa al m贸n laboral : Evoluci贸 i perspectives de futur
Aquest treball pret茅n fer un recorregut cultural, social, pol铆tic i econ貌mic de les causes que han portat a la situaci贸 actual de la dona al Jap贸 en un context temporal que es limita en els inicis del segle XX, per貌 que posa 猫mfasi en tot all貌 que pass脿 des del final de la postguerra fins a l'actualitat. L'objectiu 茅s entendre les bases sobre les que s'edifica el paper de la dona treballadora en la societat japonesa. A partir d'aquesta base i un cop analitzats els canvis que s'estan produint a nivell econ貌mic, social i pol铆tic degut a Womenomics, s'oferir脿 una opini贸 fonamentada sobre les perspectives de futur de la dona en el m贸n laboral al Jap贸.Este trabajo pretende hacer un recorrido cultural, social, pol铆tico y econ贸mico de las causas que han llevado a la situaci贸n actual de la mujer en Jap贸n en un contexto temporal que se limita en los inicios del siglo XX, pero que pone 茅nfasis en todo lo que pas贸 desde el final de la posguerra hasta la actualidad. El objetivo es entender las bases sobre las que se edifica el papel de la mujer trabajadora en la sociedad japonesa. A partir de esta base y una vez analizados los cambios que se est谩n produciendo a nivel econ贸mico, social y pol铆tico debido a Womenomics, se ofrecer谩 una opini贸n fundamentada sobre las perspectivas de futuro de la mujer en el mundo laboral en Jap贸n.Bachelor thesis for the Humanities program on East Asia