title: 15N Hyperpolarization of Imidazole-15N2for Magnetic Resonance pH Sensing via SABRE-SHEATH.
abstract: 15N nuclear spins of imidazole-15N2were hyperpolarized using NMR signal amplification by reversible exchange in shield enables alignment transfer to heteronuclei (SABRE-SHEATH). A15N NMR signal enhancement of ∼2000-fold at 9.4 T is reported using parahydrogen gas (∼50% para-) and ∼0.1 M imidazole-15N2in methanol:aqueous buffer (∼1:1). Proton binding to a15N site of imidazole occurs at physiological pH (pKa∼ 7.0), and the binding event changes the15N 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.
authors.affiliation: Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Department of Biomedical Engineering, and Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University , Nashville, Tennessee 37232-2310, United States.
authors.forename: Roman V
authors.initials: RV
authors.lastname: Shchepin
authors.affiliation: Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Department of Biomedical Engineering, and Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University , Nashville, Tennessee 37232-2310, United States.
authors.forename: Danila A
authors.initials: DA
authors.lastname: Barskiy
authors.affiliation: Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Department of Biomedical Engineering, and Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University , Nashville, Tennessee 37232-2310, United States.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Coffey
authors.affiliation: Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.
authors.forename: Thomas
authors.initials: T
authors.lastname: Theis
authors.affiliation: Department of Chemistry and Biochemistry and Materials Technology Center, Southern Illinois University , Carbondale, Illinois 62901, United States.
authors.forename: Fan
authors.initials: F
authors.lastname: Shi
authors.affiliation: Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.
authors.forename: Warren S
authors.initials: WS
authors.lastname: Warren
authors.affiliation: Department of Chemistry and Biochemistry and Materials Technology Center, Southern Illinois University, Carbondale, Illinois 62901, United States; Department of Chemistry and Biochemistry and Materials Technology Center, Southern Illinois University, Carbondale, Illinois 62901, United States.
authors.forename: Boyd M
authors.initials: BM
authors.lastname: Goodson
authors.affiliation: Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Department of Biomedical Engineering, and Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, Tennessee 37232-2310, United States; Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Department of Biomedical Engineering, and Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, Tennessee 37232-2310, United States; Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Department of Biomedical Engineering, and Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, Tennessee 37232-2310, United States; Russian Academy of Sciences, Moscow, Leninskiy Prospekt 14, 119991, Russia.
authors.forename: Eduard Y
authors.initials: EY
authors.lastname: Chekmenev
keywords: 15N; NMR; chemical shift; hyperpolarization; imidazole; pH sensing; parahydrogen