Gas phase and solution acidities: Amino acids

PHYS 362

Edward CM. Chen, ecmc@houston.rr.com1, Edward S. Chen, echen@rice.edu2, Herman Keith, hkeith@comcast.net3, and Mark Sabbagh, mark.sabbagh77@gmail.com3. (1) Natural and Applied Sciences, University of Houston, Clear Lake City, 2700 Bay Area Boulevard, Houston, TX 77058, (2) Bioinformatics Research Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, (3) Kinkaid School, 201 Kinkaid School Dr, Houston, TX 77024
The gas phase acidities of the naturally occurring amino acids are evaluated. The solution energy differences, are calculated from aqueous acidities. Three sets of values are obtained based on the different side chains which support the avalilabe GPA. Semi-empirical multiconfiguration configuration interaction calculations of bond dissociation energies and electron affinities for the molecules deprotonated radicals agree with experiment. The GPA of aspartic and glutamic acid which have just been measured were predicted from empirical and theoretical considerations. A new method of analyzing photoelectron spectra is applied to the acetate anion. The bond dissociation energies for ethyl acetate, benzyl acetate, and acetic anhydride are calculated from electron capture detector data and the electron affinity of the acetate radical. Potential experimental and theoretical methods of supporting the GPA and hydration energies are suggested based on electron impact and photoelectron spectroscopy studies of glycine.
 

PHYS Poster Session - Multiscale Modeling in Biophysics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008