Video Experimental Relacionado

Updated: Aug 21, 2025

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy

Interfacial Molecular-level Structures of Polymers and Biomacromolecules Revealed via Sum Frequency Generation Vibrational Spectroscopy

Published on: August 13, 2019

Un reportero de RMN quiral de la conformación de los pliegues en Bilayers

Siyuan Wang^1,2, Flavio Della Sala^1,2, Matthew J Cliff²

¹Department of Chemistry, University of Manchester, Oxford Road, ManchesterM13 9PL, U.K.

Journal of the American Chemical Society

|November 15, 2022

Resumen

Los investigadores desarrollaron una nueva etiqueta de reportero de fluor-19 (F) para rastrear las formas de plegado de péptidos en las membranas celulares. Esta etiqueta confirma que las conformaciones de los pliegues son consistentes entre los disolventes orgánicos y las bicapas de fosfolípidos.

Área de la Ciencia:

Biofísica y Química
Biología molecular
Ciencias de los materiales

Sus antecedentes:

El control de la conformación del pliegue de péptidos en las bicapas de fosfolípidos es crucial para su aplicación como relés de información molecular.
El desarrollo de métodos eficaces para controlar estas conformaciones en entornos de membrana es esencial.

Objetivo del estudio:

Desarrollar y utilizar una nueva etiqueta de reportero F para caracterizar las conformaciones de los pliegues de péptidos.
Investigar la influencia de los controladores quirales N-terminales en la helicidad del foldamer.
Para comparar las preferencias conformacionales de los pliegues en disolventes orgánicos frente a las bicapas de fosfolípidos.

Principales métodos:

Síntesis de los foldameros de ácido α-amino-iso-butírico (Aib) funcionalizados con la etiqueta reportera (R) -1- (trifluorometil) etilamido (R) -TFEA.
Cristalografía de rayos X para determinar las estructuras helicoidales del pliegador 3.
Espectroscopia de Resonancia Magnética Nuclear (RMN) a temperatura variable en disolventes orgánicos y en suspensiones de pequeñas vesículas unilamélicas (SUV).
Espectroscopia de RMN para correlacionar los cambios químicos con la conformación del pliegue.

Principales resultados:

La cristalografía confirmó 3 conformaciones helicoidales para los foldameros Aib.
F desplazamientos químicos de RMN del relator (R) -TFEA correlacionados con la helicidad inducida por el N-terminal (sentido de tornillo M o P) en solución.
Los espectros de RMN F en las bicapas de fosfolípidos mostraron resonancias que reflejan las de los disolventes orgánicos, lo que indica preferencias conformacionales similares.
La quiralidad de los fosfolípidos demostró una influencia mínima en la conformación del foldamer.

Conclusiones:

La etiqueta reportera (R)-TFEA monitorea efectivamente la conformación del pliegue de péptidos tanto en disolventes orgánicos como en bicapas de fosfolípidos.
Las preferencias conformacionales de Foldamer se conservan en estos diferentes entornos.
El estudio proporciona una herramienta valiosa para diseñar y controlar el comportamiento de los pliegues en sistemas de imitación de membranas.

Más Videos Relacionados

15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale

15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale

Published on: April 19, 2021

High-Pressure NMR Experiments for Detecting Protein Low-Lying Conformational States

High-Pressure NMR Experiments for Detecting Protein Low-Lying Conformational States

Published on: June 29, 2021

Videos de Conceptos Relacionados

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

¹H NMR of Conformationally Flexible Molecules: Temporal Resolution

At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...

Fischer Projections

Fischer Projections

Learning to draw Fischer projections of molecules and understanding their relevance plays a crucial role in the visual depiction of organic molecules. A Fischer projection is a two-dimensional projection on a planar surface to simplify the three-dimensional wedge–dash representation of molecules. This is especially helpful in the case of molecules with multiple chiral centers that can be difficult to draw. Here, all the bonds of interest are represented as horizontal or vertical lines.

¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR

The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.

¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons

¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons

Replacing each alpha-hydrogen in chloroethane by bromine (or a different functional group) yields a pair of enantiomers. Such protons are called prochiral or enantiotopic and are related by a mirror plane. Enantiotopic protons are chemically equivalent in an achiral environment. Because most proton NMR spectra are recorded using achiral solvents, enantiotopic hydrogens yield a single signal.
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...

Chirality

Chirality

Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...

Molecules with Multiple Chiral Centers

Molecules with Multiple Chiral Centers

Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...