%0 Generic
%9 Master's Thesis
%A Leecharoen, Rojana
%D 2005
%F pittir:7243
%K Nitric oxide; photochemistry
%T Photodynamic release of nitric oxide from nitrosothiols of glutathione and serum albumin studied by transient absorption and transient circular dichroism spectroscopy
%U http://d-scholarship-dev.library.pitt.edu/7243/
%X Nitrosation of the free sulfhydryl group in peptides and proteins leads to one of their important biological functions, as nitric oxide carriers. Nitric oxide, an important signaling free radical molecule, cannot travel to many of its important targets by itself due to its short half-life. The S-NO bond in S-nitrosopeptides or proteins, however, is both thermolytically and photolytically labile, leading to release of NO which can then attack other targets such as other amino acids and nucleotides. In this thesis, photodynamic activity of NO released from a model peptide (glutathione) and a model protein (bovine serum albumin) is studied utilizing various spectroscopic tools. The more simple linear transient absorption spectroscopy gives information on the time-scale of the photocleavage as well as that of the subsequence geminate recombination, while the more difficult transient circular dichroism will give more insightful into the conformation changes of the peptide and protein surrounding the chromophore and the direction at which the NO is being released which will enable us to explore possible targets of the photoreleased NO. In addition to experimental study, many theoretical calculations are performed to aid understanding of the results.