Structure of Gas Phase Monohydrated Nicotine: Implications for Nicotine’s Native Structure in the Acetylcholine Binding Protein
Journal Article
·
· Journal of the American Chemical Society
- Univ. of Washington, Seattle, WA (United States)
- Tokyo Institute of Technology (Japan)
- Univ. of Washington, Seattle, WA (United States); Tokyo Institute of Technology (Japan); Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
In this work, we report a joint experimental–theoretical study of the never reported before structure and infrared spectra of gas phase monohydrated nicotine (NIC) and nornicotine (NOR) and use them to assign their protonation sites. NIC’s biological activity is strongly affected by its protonation site, namely, the pyrrolidine (Pyrro-NICH+, anticipated active form) and pyridine (Pyri-NICH+) forms; however, these have yet to be directly experimentally determined in either the nicotinic acetylcholine receptor (nAChR, no water present) or the acetylcholine-binding protein (AChBP, a single water molecule is present) but can only be inferred to be Pyrro-NICH+ from the intermolecular distance to the neighboring residues (i.e., tryptophan). Our temperature-controlled double ion trap infrared spectroscopic experiments assisted by the collisional stripping method and high-level theoretical calculations yield the protonation ratio of Pyri:Pyrro = 8:2 at 240 K for the gas phase NICH+···(H2O) complex, which resembles the molecular cluster present in the AChBP. Therefore, a single water molecule in the gas phase enhances this ratio in NICH+ relative to the 3:2 for the nonhydrated gas phase NICH+ in a trend that contrasts with the almost exclusive presence of Pyrro-NICH+ in aqueous solution. In contrast, the Pyri-NORH+ protomer is exclusively observed, a fact that may correlate with its weaker biological activity.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- Japan Society for the Promotion of Science (JSPS); USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division
- Grant/Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1891995
- Report Number(s):
- PNNL-SA-172086
- Journal Information:
- Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 37 Vol. 144; ISSN 0002-7863
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Gas phase protonated nicotine is a mixture of pyridine- and pyrrolidine-protonated conformers: implications for its native structure in the nicotinic acetylcholine receptor
Switching of Protonation Sites in Hydrated Nicotine via a Grotthuss Mechanism
The Gas Phase Protonation Sites of Six Naturally Occurring Nicotinoids
Journal Article
·
Thu Dec 09 19:00:00 EST 2021
· Physical Chemistry Chemical Physics. PCCP
·
OSTI ID:1915275
Switching of Protonation Sites in Hydrated Nicotine via a Grotthuss Mechanism
Journal Article
·
Mon Jan 22 19:00:00 EST 2024
· Journal of the American Chemical Society
·
OSTI ID:2406154
The Gas Phase Protonation Sites of Six Naturally Occurring Nicotinoids
Journal Article
·
Thu Jun 27 20:00:00 EDT 2024
· Journal of Physical Chemistry Letters
·
OSTI ID:2477172