NMR Spectroscopic Characterization of the C‐Mannose Conformation in a Thrombospondin Repeat Using a Selective Labeling Approach

Abstract

Despite the great interest in glycoproteins,structural information reporting on conformation and dynamics of the sugar moieties are limited. We present an ew biochemical method to express proteins with glycans that are selectively labeled with NMR-active nuclei. We report on the incorporation of 13 C-labeled mannose in the C-mannosylated UNC-5 thrombospondin repeat. The conformational landscape of the C-mannose sugar puckers attached to tryptophan residues of UNC-5 is characterized by interconversion between the canonical 1 C 4 state and the B 03 / 1 S 3 state.T his flexibility may be essential for protein folding and stabilization. We foresee that this versatile tool to produce proteins with selectively labeled C-mannose can be applied and adjusted to other systems and modifications and potentially paves aw ay to advance glycoprotein researchb yu nravelling the dynamical and conformational properties of glycan structures and their interactions.

Glycan shield of the ebolavirus envelope glycoprotein GP

“…To accommodate realistic geometry, the tryptophan had to be repositioned slightly, albeit still in agreement with the local electron density. Care was taken to model the mannose with a ring-flipped 1 C 4 chair conformation [77–79].…”

Atom-economical synthesis of 1,2-bis(phosphine oxide)ethanes from calcium carbide with straightforward access to deuterium- and13C-labeled bidentate phosphorus ligands and metal complexes

“…[1][2][3] Labels, namely, deuterium and carbon-13, provide essential data for tuning the absorption, distribution, metabolism, and excretion of drugs. 4,5 The identification of products, [6][7][8][9][10][11][12] reaction mechanisms, [13][14][15][16][17][18][19][20][21] spectroscopy, 22 and many other applications [23][24][25][26][27][28][29][30][31][32][33] require the incorporation of a deuterium label at a specific position.…”