Racing toward Fast and Effective 17O Isotopic Labeling and Nuclear Magnetic Resonance Spectroscopy of N-Formyl-MLF-OH and Associated Building Blocks

J Phys Chem B. 2021 Nov 4;125(43):11916-11926. doi: 10.1021/acs.jpcb.1c07397. Epub 2021 Oct 25.

Abstract

Solid-state 1H, 13C, and 15N nuclear magnetic resonance (NMR) spectroscopy has been an essential analytical method in studying complex molecules and biomolecules for decades. While oxygen-17 (17O) NMR is an ideal and robust candidate to study hydrogen bonding within secondary and tertiary protein structures for example, it continues to elude many. We discuss an improved multiple-turnover labeling procedure to develop a fast and cost-effective method to 17O label fluoroenylmethyloxycarbonyl (Fmoc)-protected amino acid building blocks. This approach allows for inexpensive ($0.25 USD/mg) insertion of 17O labels, an important barrier to overcome for future biomolecular studies. The 17O NMR results of these building blocks and a site-specific strategy for labeled N-acetyl-MLF-OH and N-formyl-MLF-OH tripeptides are presented. We showcase growth in NMR development for maximizing sensitivity gains using emerging sensitivity enhancement techniques including population transfer, high-field dynamic nuclear polarization, and cross-polarization magic-angle spinning cryoprobes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids*
  • Isotope Labeling
  • Magnetic Resonance Spectroscopy
  • Nuclear Magnetic Resonance, Biomolecular
  • Proteins*

Substances

  • Amino Acids
  • Proteins