The carbonyl nucleobase adduct MAde is a potent antigen for adaptive polyclonal MR1-restricted T cells.

The major histocompatibility complex (MHC) class I-related molecule MHC-class-I-related protein 1 (MR1) presents metabolites to distinct MR1-restricted T cell subsets, including mucosal-associated invariant T (MAIT) and MR1T cells. However, self-reactive MR1T cells and the nature of recognized antigens remain underexplored. Here, we report a cell endogenous carbonyl adduct of adenine (8-(9H-purin-6-yl)-2-oxa-8-azabicyclo[3.

Nucleobase adducts bind MR1 and stimulate MR1-restricted T cells.

MR1T cells are a recently found class of T cells that recognize antigens presented by the major histocompatibility complex-I-related molecule MR1 in the absence of microbial infection. The nature of the self-antigens that stimulate MR1T cells remains unclear, hampering our understanding of their physiological role and therapeutic potential. By combining genetic, pharmacological, and biochemical approaches, we found that carbonyl stress and changes in nucleobase metabolism in target cells promote MR1T cell activation.

Pseudocontact Shifts in Biomolecular NMR Spectroscopy.

Paramagnetic centers in biomolecules, such as specific metal ions that are bound to a protein, affect the nuclei in their surrounding in various ways. One of these effects is the pseudocontact shift (PCS), which leads to strong chemical shift perturbations of nuclear spins, with a remarkably long range of 50 Å and beyond. The PCS in solution NMR is an effect originating from the anisotropic part of the dipole-dipole interaction between the magnetic momentum of unpaired electrons and nuclear spins.

A novel, rationally designed lanthanoid chelating tag delivers large paramagnetic structural restraints for biomolecular NMR.

Herein, a novel and rationally designed ortho-substituted pyridine activator is reported that reacts rapidly and selectively with cysteine thiols. It forms reduction-stable conjugates and induces large pseudocontact shifts, residual dipolar couplings and paramagnetic relaxation enhancement on both ubiquitin S57C and human carbonic anhydrase II S50C constructs under physiological conditions.

Design and applications of lanthanide chelating tags for pseudocontact shift NMR spectroscopy with biomacromolecules.

In this review, lanthanide chelating tags and their applications to pseudocontact shift NMR spectroscopy as well as analysis of residual dipolar couplings are covered. A complete overview is presented of DOTA-derived and non-DOTA-derived lanthanide chelating tags, critical points in the design of lanthanide chelating tags as appropriate linker moieties, their stability under reductive conditions, e.g.

Structure of formylglycine-generating enzyme in complex with copper and a substrate reveals an acidic pocket for binding and activation of molecular oxygen.

The formylglycine generating enzyme (FGE) catalyzes oxidative conversion of specific peptidyl-cysteine residues to formylglycine. FGE mediates O-activation and hydrogen-atom abstraction in an active site that contains Cu(i) coordinated to two cysteine residues. Similar coordination geometries are common among copper-sensing transcription factors and copper-chaperone but are unprecedented among copper-dependent oxidases.

P4T-DOTA - a lanthanide chelating tag combining a sterically highly overcrowded backbone with a reductively stable linker.

Herein we report a DOTA-based lanthanide chelating tag (LCT) with rigidified backbone and a reduction-stable linker. The newly developed tag induces strong pseudocontact shifts suitable for paramagnetic protein nuclear magnetic resonance spectroscopy and the obtained anisotropic susceptibility parameters are in the range of the best performing LCTs.

A Sterically Overcrowded, Isopropyl-Substituted, Lanthanide-Chelating Tag for Protein Pseudocontact Shift NMR Spectroscopy: Synthesis of its Macrocyclic Scaffold and Benchmarking on Ubiquitin S57 C and hCA II S166 C.

A sterically overcrowded lanthanide-chelating tag has been synthesized in order to investigate the influence on the obtained pseudocontact shifts and the anisotropic part of the magnetic susceptibility tensor compared to those of its predecessor DOTA-M8-(4R,4S)-SSPy. For the first time, a concise synthetic route is presented for isopropyl-substituted cyclen, the macrocyclic scaffold of the lanthanide-chelating tag, delivering the macrocycle in an overall yield of 6 % over 11 steps. The geometry of the lutetium complex has been assigned by ROESY experiments, adopting exclusively a Λ(δδδδ) conformation, and DFT calculations have confirmed a stabilization of 32.

Localization of ligands within human carbonic anhydrase II using F pseudocontact shift analysis.

Unraveling the native structure of protein-ligand complexes in solution enables rational drug design. We report here the use of F pseudocontact shift (PCS) NMR as a method to determine fluorine positions of high affinity ligands bound within the drug target human carbonic anhydrase II with high accuracy. Three different ligands were localized within the protein by analysis of the obtained PCS from simple one-dimensional F spectra with an accuracy of up to 0.

Synthesis of chiral nine and twelve-membered cyclic polyamines from natural building blocks.

A rational strategy for the facile and efficient cyclization of amino acid-based linear precursors forming nine and twelve-membered cyclic peptidomimetics is reported. The resulting chiral lactams can readily be reduced to substituted cyclic polyamine analogues of 1,4,7,10-tetraaza-cyclododecane (cyclen) and 1,4,7-triaza-cyclononane (TACN).

Conformationally locked lanthanide chelating tags for convenient pseudocontact shift protein nuclear magnetic resonance spectroscopy.

Pseudocontact shifts (PCS) generated by lanthanide chelating tags yield valuable restraints for investigating protein structures, dynamics and interactions in solution. In this work, dysprosium-, thulium- and terbium-complexes of eight-fold methylated 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid tags [DOTA-M8-(4R4S)-SSPy] are presented that induce large pseudocontact shifts up to 5.5 ppm and adopt exclusively the square antiprismatic conformation.