title: Hydrogen-bond accepting strength of protonated nicotine.
abstract: Recent crystal structures of nicotine bound to the acetylcholine binding protein (AChBP) ended a long debate confirming that the pyridine nitrogen of nicotine is indeed hydrogen-bonded to receptor residues through a bridging water molecule. Here, we describe the first direct experimental evaluation of the hydrogen-bond affinity of the nicotinium pyridine nitrogen. The equilibrium constant of its association with a phenol is 1 order of magnitude greater than the association of the acetylcholine carbonyl oxygen.
authors.forename: Virginie
authors.initials: V
authors.lastname: Arnaud
authors.forename: Michel
authors.initials: M
authors.lastname: Berthelot
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Le Questel
mesh_terms: D000109:Acetylcholine / Q000737:chemistry; D002627:Chemistry, Physical / Q000379:methods*; D003720:Densitometry; D006860:Hydrogen Bonding; D007700:Kinetics; D008752:Methylene Chloride / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D009538:Nicotine / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D019800:Phenol / Q000737:chemistry; D011522:Protons; D011725:Pyridines / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D011522:Protons; D011725:Pyridines; D019800:Phenol; D008752:Methylene Chloride; D009538:Nicotine; D009584:Nitrogen; D000109:Acetylcholine; D010100:Oxygen