Parahydrogen-induced polarization enables the single-scan NMR detection of a 236 kDa biopolymer at nanomolar concentrations

• Published in: Scientific reports Vol. 13; no. 1; p. 10117
• Main Authors: Theiss, Franziska, Wienands, Laura, Lins, Jonas, Alcaraz-Janßen, Marcel, Thiele, Christina M, Buntkowsky, Gerd
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 21.06.2023; Nature Publishing Group UK; Nature Portfolio
• Subjects: Biopolymers; Chemistry; Experiments; Glutamic acid; Hydrogenation; Hyperpolarization; Molecular weight; NMR; Nuclear magnetic resonance; Polymers; Protons
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-37202-0

Nuclear magnetic resonance (NMR) experiments utilizing parahydrogen-induced polarization (PHIP) were performed to elucidate the PHIP activity of the synthetic 236 kDa biopolymer poly-γ-(4-propargyloxy)-benzyl-L-glutamate) (PPOBLG). The homopolypeptide was successfully hyperpolarized and the enhanced signals were detected in 11.7 T solution NMR as a function of the PPOBLG concentration. The hydrogenation with parahydrogen caused signal enhancements of 800 and more for the vinyl protons of the side chain at low substrate concentration. As a result of this high enhancement factor, even at 13 nM of PPOBLG, a single scan H-NMR detection of the hyperpolarized protons was possible, owing to the combination of hyperpolarization and density of PHIP active sites.