Stable Isotopes for Biomolecular NMR Spectroscopy

Structure Determination of Proteins and Biomolecules

Biomolecular NMR enables the identification of three-dimensional structures of biomolecules in solution. It provides information on secondary structures, such as alpha helices and beta sheets, while also revealing details of molecular dynamics and structural flexibility. This capability allows researchers to study macromolecules under conditions that closely mimic physiological environments, providing critical insight into their biological functions.

Dynamics and Interactions in Structural Biology

One of the major advantages of biomolecular NMR is its ability to study molecular dynamics and interactions in real time. The technique allows researchers to quantify binding affinities, monitor conformational changes, and assess the stability of protein complexes. These capabilities make biomolecular NMR particularly valuable in pharmaceutical research, contributing to lead generation and fragment-based drug discovery processes.

Isotope Labeling in Conformational Biomolecular NMR Spectroscopy

Due to the sensitivity limitations of NMR, biomolecules are often isotopically labeled with stable isotopes such as ¹³C and ¹⁵N. This labeling enhances signal detection and allows more detailed analysis of larger macromolecules. Researchers use various techniques, including sparse labeling and methyl labeling, to optimize spectral quality and resolution. These methods expand the range of biological systems that can be effectively studied using NMR spectroscopy.

Silantes uses biotechnological methods to produce stable isotope-labeled biomolecules from microorganisms such as bacteria, yeast and algae. Our webshop offers proteins and protein building blocks, as well as RNA and DNA molecules and their building blocks in a variety of labeling schemes.

²H Labeling NMR Spectroscopy Applications

In NMR spectroscopy of biological samples, deuterium (²H) labeling is a very useful technique. It involves replacing hydrogen atoms with deuterium, which has different nuclear spin properties. This labeling method offers several advantages for structural and dynamic studies of proteins and other biomolecules. Deuteration can reduce spectral complexity through the elimination of proton signals, improve resolution through the removal of certain dipolar couplings, and provide insight into molecular motions.

Common applications include selective labeling of methyl groups in amino acids such as alanine, leucine, and valine to study protein dynamics. Complete protein perdeuteration allows high-resolution studies of large proteins. In addition, ²H labeling can be strategically used with other isotopes such as ¹³C and ¹⁵N for multidimensional NMR experiments, expanding the toolkit for studying complex biological systems.

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¹⁹F Labeling NMR Spectroscopy Applications

The ¹⁹F (fluorine) labeling technique is a powerful tool in the NMR spectroscopy study of macromolecular complexes and protein chemistry. It exploits the 100% natural abundance and high NMR sensitivity of the ¹⁹F nucleus to provide structural and functional insight. Key advantages include a clean background, and consequently the spectrum, due to the absence of fluorine in most biological systems, high sensitivity to local environmental changes, and applicability to both solution and solid-state NMR.

Common approaches include the incorporation of fluorinated amino acids during protein synthesis or the chemical modification of specific residues. ¹⁹F labeling has found applications in drug discovery, protein folding studies, and the study of biomolecular interactions in complex cellular environments.

Advancing RNA and DNA Research

Biomolecular NMR spectroscopy is a powerful technique for elucidating the structures and dynamics of RNA and DNA molecules, providing critical insight into molecular biology and drug discovery. It has been particularly instrumental in RNA structure determination, allowing researchers to analyze molecules and reveal complex details about their conformations and interactions.

Silantes offers a full range of products and services to support NMR studies of nucleic acids. Leveraging our years of experience, we offer a comprehensive line of isotope-labeled RNA and DNA building blocks, including NTPs and phosphoramidites, as well as specialized oligonucleotide synthesis services.

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Stable Isotopes for NMR Studies of the Structure and Interactions of RNA

Stable isotopes are widely used in NMR studies of RNA structure and dynamics. Isotopic labeling of RNA samples is used to reduce spectral overlap and allow through-bond NMR experiments necessary for 3D structure determination. Various labeling methods with stable isotopes such as ¹³C, and ¹⁵N, and ¹⁹F are used in sample preparation, either by solid phase synthesis or enzymatic in vitro transcription.

Specific examples of isotopic labeling include deuteration of RNA samples to reduce the number of cross peaks, incorporation of ¹⁹F –¹³C spin pairs into pyrimidine residues to probe RNA structure, and ¹⁵N labeling to study hydrogen bonding in base pairs. These labeling strategies allow advanced NMR techniques such as TROSY experiments on large RNAs.

In-cell NMR experiments use ¹⁹F labeling to study RNA in the cellular environment, taking advantage of the absence of ¹⁹F in cells. Overall, these isotopic labeling approaches are essential for the application of modern NMR methods to elucidate RNA structure, dynamics, and interactions at atomic resolution.

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Advancing Protein Research

Stable isotope labeling of proteins is a critical technique in NMR spectroscopy that allows researchers to obtain detailed structural and functional information about these complex biomolecules. By incorporating stable isotopes into proteins, scientists can distinguish protein signals from other sample components, leading to more precise analyses of protein structure, dynamics, and interactions.

Silantes offers a comprehensive suite of solutions to support these advanced protein studies. We have developed and produce our own line of stable isotope-labeled growth media for various organisms. We also offer an extensive range of isotope-labeled amino acids and NMR-quality model proteins.

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