Diphtheria toxin inactivates protein synthesis elongation factor 2 by attaching ADP-ribose to an unusual post-translational amino acid derivative, diphthamide, in the factor. Previously, we prepared ribosyl-diphthamide from the ADP-ribosyl-factor and proposed on the basis of NMR spectral analysis that it is 1-alpha-D-ribofuranosyl-2-[3-carboxyamido-3-(trimethylammonio++ +)propyl] histidine [N. J. Oppenheimer, and J.W. Bodley, (1981) J. Biol. Chem. 256, 8579-8581 and op. cit.]. Now, using fast atom bombardment mass spectrometry, the intact cation of ribosyl-diphthamide has been observed in the gas phase. The theoretical mass of the structure proposed for ribosyl-diphthamide uniquely agrees with the observed mass of the inact cation of the compound to within 2 ppm. Collisional activation decomposition mass spectral analysis provided additional structural confirmation. Thus, although the compound has not been synthesized, all available evidence appears uniquely consistent with the structure of ribosyl-diphthamide previously proposed.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0003-9861(84)90439-9 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Machine-Learning Modeling of Elemental Ferroelectric Bismuth Monolayer.
Phys Rev Lett
December 2024
Xi'an Jiaotong University, School of Microelectronics & State Key Laboratory for Mechanical Behavior of Materials, Xi'an 710049, China.
The bismuth monolayer has recently been experimentally identified as a novel platform for the investigation of two-dimensional single-element ferroelectric system. Here, we model the potential energy surface of a bismuth monolayer by employing a message-passing neural network and achieve an error smaller than 1.2 meV per atom.
View Article and Find Full Text PDFHolographic light potentials generated by phase-modulating liquid-crystal spatial light modulators (SLMs) are widely used in quantum technology applications. Accurate calibration of the wavefront and intensity profile of the laser beam at the SLM display is key to the high fidelity of holographic potentials. Here, we present a new calibration technique that is faster than previous methods while maintaining the same level of accuracy.
View Article and Find Full Text PDFFast single atom imaging for optical lattice arrays.
Nat Commun
January 2025
Department of Physics, Harvard University, Cambridge, MA, USA.
High-resolution fluorescence imaging of ultracold atoms and molecules is paramount to performing quantum simulation and computation in optical lattices and tweezers. Imaging durations in these experiments typically range from a millisecond to a second, significantly limiting the cycle time. In this work, we present fast, 2.
View Article and Find Full Text PDFFluidized Electrochemical Exfoliation of Layered Transition Metal Dichalcogenides toward Fast Production of High-Quality Nanosheets in the Aqueous Phase.
Nano Lett
January 2025
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
The transformation of bulk transition-metal dichalcogenide (TMD) particles into ultrathin nanosheets with both an acceptable yield and preserved crystalline integrity presents a substantial challenge in electrochemical exfoliation. This challenge arises from the continuous potential stress that the materials experience in traditional exfoliation setups. Herein, we propose a new fluidized electrochemical exfoliation (FEE) method to efficiently transform TMD powders into high-quality, few-layered TMD nanosheets in the aqueous phase.
View Article and Find Full Text PDFAccelerating Quantum Anharmonic Vibrational Calculations by Atom-Specific Hybrid Basis Set-Based Potential Energy Surface Approach.
J Phys Chem A
January 2025
Department of Chemistry and Chemical Sciences, Central University Jammu, Samba 181143, Jammu and Kashmir, India.
The development of accurate yet fast quantum mechanical methods to calculate the anharmonic vibrational spectra of large molecules is one of the major goals of ongoing developments in this field. This study extensively explores and validates a hybrid electronic basis set approach for anharmonic vibrational calculations, where the molecule is segregated into different computational layers, and such layers are then treated with different levels of electronic basis sets. Following the system-bath model, the atoms corresponding to the active sites are treated in more accurate but computationally slower, large basis set and the rest of the atoms in less accurate but computationally faster, small basis set to construct the anharmonic hybrid potential energy surface (PES).
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!