TY - JOUR
T1 - Ab Initio Investigation of the Hydration of Deprotonated Amino Acids
AU - Michaux, Catherine
AU - Wouters, Johan
AU - Perpète, Eric A.
AU - Jacquemin, Denis
PY - 2009/4/1
Y1 - 2009/4/1
N2 - The complexation of five deprotonated anionic amino acids (glycine, L-alanine, L-valine, L-Aspartic acid, and L-glutamine) with one water molecule, has been investigated using a MP2/63-11++G(d,p) approach fully accounting for the basis set superposition errors. For each amino acid, several energetic minima have been identified, and we provide spectroscopic information allowing to discriminate them. Our results strongly suggest that two complexes should coexist under the experimental conditions for [Ala - H]-, [Val - H]-, and [Asp - H]-. Comparisons with the experimental enthalpies, entropies, and Gibbs free energies recently obtained by Wincel [J. Am. Soc. Mass Spectrom. 2008, 19, 1091-1097] show that our simulation reproduces the most significant structure/energy experimental trends, though the entropic changes induced by hydration are slightly overestimated.
AB - The complexation of five deprotonated anionic amino acids (glycine, L-alanine, L-valine, L-Aspartic acid, and L-glutamine) with one water molecule, has been investigated using a MP2/63-11++G(d,p) approach fully accounting for the basis set superposition errors. For each amino acid, several energetic minima have been identified, and we provide spectroscopic information allowing to discriminate them. Our results strongly suggest that two complexes should coexist under the experimental conditions for [Ala - H]-, [Val - H]-, and [Asp - H]-. Comparisons with the experimental enthalpies, entropies, and Gibbs free energies recently obtained by Wincel [J. Am. Soc. Mass Spectrom. 2008, 19, 1091-1097] show that our simulation reproduces the most significant structure/energy experimental trends, though the entropic changes induced by hydration are slightly overestimated.
UR - http://www.scopus.com/inward/record.url?scp=62149126999&partnerID=8YFLogxK
U2 - 10.1016/j.jasms.2008.11.025
DO - 10.1016/j.jasms.2008.11.025
M3 - Article
C2 - 19185508
AN - SCOPUS:62149126999
SN - 1044-0305
VL - 20
SP - 632
EP - 638
JO - Journal of the American Society for Mass Spectrometry
JF - Journal of the American Society for Mass Spectrometry
IS - 4
ER -