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Biology subjects

Delaglio, F.

Publications and source records attributed to Delaglio, F..

3 recordsLinked to original sources

Metabolite Fraction Libraries for Quantitative NMR Metabolomics

Nuclear Magnetic Resonance (NMR) has unique strengths in metabolomics studies, particularly in quantifying mixtures and elucidating the structures of unknown molecules. One-dimensional (1D) proton (1H) NMR is the most common method; however, spectral overlap is significant, making analysis challenging. We present a new approach that utilizes chromatographically separated fractions from a pooled sample, henceforth called a metabolite fraction library (mFL). We developed an algorithm to extract highly correlated peaks from the mFL, collectively forming a metabolite basis set (mBS). The mBS can be fit to NMR profiling data, enabling comprehensive quantification. Applied to 10 mixtures of 53 metabolites, our approach accurately quantified 50, quantified an impurity and an oxidation product, and described between 91-96% of total spectral intensity. The method is demonstrated using the fungus Neurospora crassa, resulting in the identification of 45 metabolites with high confidence, 45 with medium confidence, and accounting for 94% of total spectral intensity.

bioinformatics↗

Top-Down Scoring of Spectral Fitness by Image Analysis for Protein Structure Validation

Nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for protein structure determination, but traditional approaches require extensive manual assignment of hundreds to thousands of resonances. Here we present NMRFAM-BPHON, a novel "top-down" approach that treats experimental NMR spectra as continuous grayscale images and quantitatively scores the agreement with simulated spectra generated from candidate protein structures. This method does not require complete resonance assignments, though it can incorporate experimental chemical shifts when available to improve performance. The simulated spectra are generated from postulated resonance assignments, which can be derived either from empirical database predictions, direct interpretation, or a hybrid combination. BPHON employs a physics-based approximate polarization transfer model to predict cross-peak intensities from the internuclear distances in the decoy structure, and models the peak lineshapes using empirical, bulk T2 relaxation rates and literature values for scalar couplings. The resulting simulated spectra are scored relative to the experimental data by normalized cross correlation, yielding a fitness score between 0 and 1. We demonstrate BPHONs ability to discriminate structural models, particularly in the case of 13C-detected magic angle spinning solid-state NMR spectra. The software is packaged with a user-friendly graphical user interface for ChimeraX, enabling advanced NMR analysis accessible without requiring extensive manual analysis.

biophysics↗

NMRdock: Lightweight and Modular NMR Processing

NMR is a widely employed tool in chemistry, biology, and physics for the study of molecular structure and dynamics. Advances in computation have produced scores of software programs necessary for the processing and analysis of NMR data. However, the production of NMR software has been largely overseen by academic labs, each with their own preferred OS, environment, and dependencies. This lack of broader standardization and the complexity of installing and maintaining NMR-related software creates a barrier of entry into the field. To further complicate matters, as computation evolves, many aging software packages become deprecated. To reduce the barrier for newcomers and to prevent deprecation of aging software, we have created the NMRdock container. NMRdock utilizes containerization to package NMR processing and analysis programs into a single, easy-to-install Docker image that can be run on any modern OS. The current image contains two bedrock NMR data processing programs (NMRPipe and NMRFAM Sparky). However, future development of NMRdock aims to add modules for additional analysis programs to build a library of tools in a standardized and easy-to-implement manner. NMRdock is open source and free to download at https://compbiocore.github.io/nmrdock/.

biophysics↗