Kiryutin, Alexey S., Grit Sauer, Daniel Tietze, Martin Brodrecht, Stephan Knecht, Alexandra V. Yurkovskaya, Konstantin L. Ivanov, Olga Avrutina, Harald Kolmar, and Gerd Buntkowsky. “Ultrafast Single‐Scan 2D NMR Spectroscopic Detection of a PHIP‐Hyperpolarized Protease Inhibitor.” Chemistry – A European Journal 25, no. 16 (March 15, 2019): 4025–30.
Two-dimensional (2D) NMR is one of the most important spectroscopic tools for the investigation of biological macromolecules. However, owing to the low sensitivity of NMR it takes usually from several minutes to many hours to record such a spectrum. Here we show that a bioactive derivative of the sunflower trypsin inhibitor-1 (SFTI-1), a tetradecapeptide, can be detected by the combination of parahydrogen-induced polarization (PHIP) and ultrafast 2D-NMR spectroscopy (in the following abbreviated as 2D-NMR). The PHIP activity of the inhibitor was achieved by labeling with O-propargyl-Ltyrosine. In 1D-PHIP experiments an enhancement of approximately 1200 compared to normal NMR was found. This enhancement permits measurement of 2D-NMR correlation spectra of low concentrated SFTI-1 in less than 10 seconds, employing ultrafast single-scan 2D-NMR detection. As experimental examples PHIP assisted ultrafast single-scan TOCSY spectra of SFTI-1 are shown.