Hydrogen−Deuterium Exchange and Selective Labeling of Deprotonated Amino Acids and Peptides in the Gas Phase
作者:Zhixin Tian、Lev Lis、Steven R. Kass
DOI:10.1021/ja076599l
日期:2008.1.1
Hydrogen-deuterium exchange reactions of deprotonated aminoacids and small peptides were studied. Selective labeling can be carried out at the alpha-amino group of lysine (2 of 4 labile hydrogens undergo exchange with CF3CH2OD) and the guanidine sidechain of arginine (3 of 6 labile hydrogens undergo exchange with CH3CH2OD and C6H5CH2OD). Differential labeling of peptides also was accomplished, and the extent of
An Experimental and Computational Investigation into the Gas-Phase Acidities of Tyrosine and Phenylalanine: Three Structures for Deprotonated Tyrosine
作者:Samantha S. Bokatzian、Michele L. Stover、Chelsea E. Plummer、David A. Dixon、Carolyn J. Cassady
DOI:10.1021/jp510037c
日期:2014.11.6
The structures were distinguished experimentally by ion/molecule reactions involving proton transfer and trimethylsilyl azide. Gas-phase acidities from proton transfer reactions and from G3(MP2) calculations generally agree well. The lowest energy structure, which was only observed experimentally using electrospray ionization fromaproticsolvents, is deprotonated at the carboxylic acid group and is
Thermodynamic studies about the interaction of scorpiand aza-macrocycles with amino acids in water show entropy driven stabilisations often associated with solvation/desolvation processes.