Related Experiment Video
Updated: Jul 28, 2025
08:09
15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale
Published on: April 19, 2021
5.3K
Elongated Bacterial Pili as a Versatile Alignment Medium for NMR Spectroscopy
Sirine Nouri1, Julien Boudet2, Hiang Dreher-Teo2
1Centre de RMN à Très Hauts Champs, CNRS, ENSL, UCBL, Université de Lyon, 5 rue de la Doua, 69100, Villeurbanne, France.
Angewandte Chemie (International Ed. in English)
|May 29, 2023
Summary
Bacterial type 1 pili serve as a novel alignment medium for measuring residual dipolar couplings (RDCs) in NMR spectroscopy. This stable, versatile medium aids in characterizing molecular structure and dynamics for proteins, nucleic acids, and small molecules.
Area of Science:
- Biophysical Chemistry
- Structural Biology
- NMR Spectroscopy
Background:
- Residual dipolar couplings (RDCs) are crucial for determining molecular structure and dynamics using NMR spectroscopy.
- Measuring RDCs requires partial alignment of molecules, typically achieved with liquid crystals.
Purpose of the Study:
- To introduce bacterial type 1 pili as a novel liquid-crystalline alignment medium for RDC measurements.
- To demonstrate the utility of type 1 pili for NMR analysis of diverse molecules.
Main Methods:
- Elongating wild-type type 1 pili via recombinant overproduction of the main subunit.
- Utilizing elongated pili as an alignment medium for NMR spectroscopy.
- Testing compatibility with various experimental conditions (temperature, pH, solvents, detergents).
Main Results:
- Bacterial type 1 pili effectively align molecules for RDC measurements.
- The pili-based medium is stable under harsh experimental conditions, unlike many existing media.
- Applicability demonstrated for proteins (ubiquitin), nucleic acids (HIV-1 TAR RNA), and small molecules (camphor).
Conclusions:
- Bacterial type 1 pili offer a robust and versatile alternative alignment medium for RDC determination.
- This method enhances the characterization of molecular structure and dynamics via NMR spectroscopy.
Related Concept Videos
01:28Fimbriae, Pili, and Axial Filaments
66
Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...
66
01:27¹H NMR: Long-Range Coupling
1.8K
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
1.8K
01:25Applications Of NMR In Biology
3.8K
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
3.8K
01:15Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
415
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...
415
01:29Cytoskeletal Proteins in Bacteria
3.5K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.5K
01:09¹H NMR: Pople Notation
1.8K
The Pople nomenclature system classifies spin systems based on the difference between their chemical shifts. Coupled spins are denoted by capital letters with subscripts indicating the number of equivalent nuclei. When the coupled nuclei have well-separated chemical shifts, they are assigned letters that are far apart in the alphabet, such as A and X. When the difference in chemical shifts is small, coupled nuclei are named using adjacent letters of the alphabet (AB, MN, or XY).
A proton...
A proton...
1.8K