Publications [#328167] of Warren S. Warren

Journal Articles
  1. Shchepin, RV; Barskiy, DA; Coffey, AM; Theis, T; Shi, F; Warren, WS; Goodson, BM; Chekmenev, EY, 15N Hyperpolarization of Imidazole-15N2 for Magnetic Resonance pH Sensing via SABRE-SHEATH., Acs Sensors, vol. 1 no. 6 (June, 2016), pp. 640-644 [doi] .

    15N nuclear spins of imidazole-15N2 were hyperpolarized using NMR signal amplification by reversible exchange in shield enables alignment transfer to heteronuclei (SABRE-SHEATH). A 15N NMR signal enhancement of ∼2000-fold at 9.4 T is reported using parahydrogen gas (∼50% para-) and ∼0.1 M imidazole-15N2 in methanol:aqueous buffer (∼1:1). Proton binding to a 15N site of imidazole occurs at physiological pH (pKa ∼ 7.0), and the binding event changes the 15N isotropic chemical shift by ∼30 ppm. These properties are ideal for in vivo pH sensing. Additionally, imidazoles have low toxicity and are readily incorporated into a wide range of biomolecules. 15N-Imidazole SABRE-SHEATH hyperpolarization potentially enables pH sensing on scales ranging from peptide and protein molecules to living organisms.