Changes in the Emission Intensity due to in situ Photoreactions

        S. Aranganathan1, T.K.S.Kumar2, C.Yu2* and Der-Hang Chin1*



1.        Department of Chemistry, National Changhua University of  Education, Changhua,   Taiwan

2.       Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan


The protein samples exposed to light in a spectrofluorimeter are found to undergo in situ photoreactions. Continuous irradiation of proteins results in progressive decrease in the emission intensity. The light-induced changes are irreversible and appear to be oxygen-dependent. Continuous exposure to light renders the protein susceptible to cleavage. Further, the temperature-induced unfolding of proteins appears to be significantly influenced by the photoreactions caused due to irradiation. Some of the photosensitized reactions were also performed in light receptive Neocarzinostatin.


















* To whom all correspondence has to be addressed. Fax-886-47211190.This work was supported by grants from the National Health Research Institutes, Taiwan.