3-Mercapto-2,6-Pyridinedicarboxylic Acid: A Small Lanthanide-Binding Tag for Protein Studies by NMR Spectroscopy

✍ Scribed by Bradley Man; Xun-Cheng Su; Haobo Liang; Shane Simonsen; Thomas Huber; Barbara A. Messerle; Gottfried Otting

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 375 KB
• Volume: 16
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200902904

✦ Synopsis

Abstract

Paramagnetic effects from lanthanide ions present powerful tools for protein studies by nuclear magnetic resonance (NMR) spectroscopy provided that the lanthanide can be site‐specifically and rigidly attached to the protein. A new, particularly small and rigid lanthanide‐binding tag, 3‐mercapto‐2,6‐pyridinedicarboxylic acid (3MDPA), was synthesized and attached to two different proteins via a disulfide bond. The complexes of the N‐terminal domain of the E. coli arginine repressor (ArgN) with seven different paramagnetic lanthanide ions and Co^2+^ were analyzed in detail by NMR spectroscopy. The magnetic susceptibility anisotropy (Δ__χ__) tensors and metal position were determined from pseudocontact shifts. The 3MDPA tag generated very different Δ__χ__ tensor orientations compared to the previously studied 4‐mercaptomethyl‐DPA tag, making it a highly complementary and useful tool for protein NMR studies.