The structure of two protected amino acids, FMOC-l-leucine and FMOC-l-valine, and a dipeptide, N-acetyl-l-valyl-l-leucine (N-Ac-VL), were studied via one- and two-dimensional solid-state nuclear magnetic resonance (NMR) spectroscopy. Utilizing O magic-angle spinning (MAS) NMR at multiple magnetic fields (17.6-35.2 T/750-1500 MHz for H) the O quadrupolar and chemical shift parameters were determined for the two oxygen sites of each FMOC-protected amino acids and the three distinct oxygen environments of the dipeptide. The one- and two-dimensional, O, N-O, C-O, and H-O double-resonance correlation experiments performed on the uniformly C,N and 70% O-labeled dipeptide prove the attainability of O as a probe for structure studies of biological systems. N-O and C-O distances were measured via one-dimensional REAPDOR and ZF-TEDOR experimental buildup curves and determined to be within 15% of previously reported distances, thus demonstrating the use of O NMR to quantitate interatomic distances in a fully labeled dipeptide. Through-space hydrogen bonding of N-Ac-VL was investigated by a two-dimensional H-detected O R-R-INEPT experiment, furthering the importance of O for studies of structure in biomolecular solids.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8256432 | PMC |
| http://dx.doi.org/10.1021/jacs.7b08989 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Carving Metal-Organic-Framework Glass Based Solid-State Electrolyte Via a Top-Down Strategy for Lithium-Metal Battery.
Angew Chem Int Ed Engl
January 2025
KU Leuven, Materials engineering, Kasteelpark Arenberg 44 bus 2450, 3001 LEUVEN Belgium, LEUVEN, BELGIUM.
Traditional polymer solid electrolytes (PSEs) suffer from low Li conductivity, poor kinetics and safety concerns. Here, we present a novel porous MOF glass gelled polymer electrolyte (PMG-GPE) prepared via a top-down strategy, which features a unique three-dimensional interconnected graded-aperture structure for efficient ion transport. Comprehensive analyses, including time-of-flight secondary ion mass spectrometry (TOF-SIMS), Solid-state 7Li magic-angle-spinning nuclear magnetic resonance (MAS-NMR), Molecular Dynamics (MD) simulations, and electrochemical tests, quantify the pore structures, revealing their relationship with ion conductivity that increases and then decreases as macropore proportion rises.
View Article and Find Full Text PDFConstruction of Luminescent Three-Dimensional Covalent Organic Frameworks for Molecular Decoding of Wide Organic Compounds.
Chem Asian J
January 2025
Qingdao University of Science and Technology, College of Polymer Science and Engineering, 53 ZHENGZHOU ROAD, 266000, Qingdao, CHINA.
Constructing highly conjugated three-dimensional covalent organic frameworks (3D COFs), particularly those with luminescent features, remains a significant challenge. In this work, we successfully synthesized a 3D COF, named 3D-Py-SP-COF, using a rigid and orthogonal spirobifluorene building block for the spatial 3D structure construction and planar pyrene as luminescent units. The incorporation of the pyrene and the unique rigid 3D network structure endow 3D-Py-SP-COF with fluorescent properties.
View Article and Find Full Text PDFOlive Fruit Phenolic Profiling Using High Resolution-Magic Angle Spinning (HR-MAS) Solid-State NMR Spectroscopy.
Methods Mol Biol
January 2025
NMR Laboratory, Chemistry Department, University of Crete, Heraklion, Crete, Greece.
High Resolution-Magic Angle Spinning (HR-MAS) solid-state NMR spectroscopy is finding increasing application in the analysis of solid foods, bypassing the need for complicated solvent extraction procedures. In the present protocol, we report a simple analytical approach based on HR-MAS NMR spectroscopy for the phenolic profiling of olive fruits, flesh, or skin. This approach allows the facile characterization of phenolic compounds in olive fruits cultivated for extra-virgin olive oil production as a function of maturation and variety, in addition to processing technology for table olives.
View Article and Find Full Text PDFDACH-Based Chiral Sensing Platforms as Tunable Benzamide-Chiral Solvating Agents for NMR Enantioselective Discrimination.
Anal Chem
January 2025
School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun 113001, China.
Chiral discrimination is an indispensable tool that has pivotal importance in the assignment of absolute configuration and determination of enantiomeric excess in chiral compounds. A series of enantiomerically pure -1,2-diaminocyclohexane (-DACH)-derived benzamides were first synthesized by simple chemical steps, and 14 variated derivatives have been assessed as NMR chiral solvating agents (CSAs) for discrimination of the signals of mandelic acid (MA) in H NMR analysis. The highly efficient chiral recognition of CSA on different substrates, including MAs, carboxylic acids, amino acid derivatives, and phosphoric acids (32 examples), was expanded via H, F, and P NMR spectroscopy.
View Article and Find Full Text PDFInvestigating Cell Wall Diffusion in Wood Modified with Phenol Urea Formaldehyde Resin in Different Length Scales.
Biomacromolecules
January 2025
BioComposites Centre, Bangor University, Bangor LL57 2UW, U.K.
Wood modification using low molecular weight thermosetting resins improves the biological durability and dimensional stability of wood while avoiding increasingly regulated biocides. During the modification process, resin monomers diffuse from the cell lumen to the cell wall, occupying micropore spaces before curing at 150 °C. This study investigated the mechanism of cell wall diffusion at multiple scales, comparing two test groups where diffusion was either facilitated or restricted.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!