Biochemical and Biophysical Changes Induced by Fungicide Sodium Diethyl Dithiocarbamate (SDD), in Phytocystatin Purified from Phaseolus mungo (Urd): A Commonly Used Indian Legume
详细信息 查看全文
- 作者：Sandeep Sharma ; Fouzia Rashid ; and Bilqees Bano
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2005
- 出版时间：July 27, 2005
- 年：2005
- 卷：53
- 期：15
- 页码：6027 - 6034
- 全文大小：334K
- 年卷期：v.53,no.15(July 27, 2005)
- ISSN：1520-5118
文摘
Phytocystatins are the plant thiol protease inhibitors involved in several reaction mechanisms of theplant system like regulation of proteolytic activity and storage of proteins. Biochemical and biophysicalchanges induced by fungicide SDD in phytocystatin purified from Phaseolus mungo have beeninvestigated in terms of mass spectroscopy, Fourier transform infrared spectroscopy, and fluorescencespectroscopy, at pH 7.0, with varying fungicide concentrations (1-9 mM) and a time of incubationranging from 2 to 8 h at 37 
C, with a fixed cystatin concentration (1.5 mM). Reactive oxygen speciesresponsible for inhibitor damage were also investigated, and thiourea was found to scavenge thefree radicals generated by SDD. FTIR analysis indicates a significant conformational transition from
-helix to 
-sheet structure; quenching of fluorescence is evident by fluorescence spectroscopy. Theactivity assay showed a decrease in inhibitory activity, as well as a fragmentation of the inhibitor wasobserved in electrophoresis. Results obtained implicate that exposure of phytocystatins to SDDinvolves physicochemical changes in cystatins leading to damage and a decrease in the activity ofthe inhibitor.Keywords: SDD; Fourier transform infrared spectroscopy; fluorescence spectroscopy; proteaseinhibitor; proteins
C, with a fixed cystatin concentration (1.5 mM). Reactive oxygen speciesresponsible for inhibitor damage were also investigated, and thiourea was found to scavenge thefree radicals generated by SDD. FTIR analysis indicates a significant conformational transition from-helix to -sheet structure; quenching of fluorescence is evident by fluorescence spectroscopy. Theactivity assay showed a decrease in inhibitory activity, as well as a fragmentation of the inhibitor wasobserved in electrophoresis. Results obtained implicate that exposure of phytocystatins to SDDinvolves physicochemical changes in cystatins leading to damage and a decrease in the activity ofthe inhibitor.Keywords: SDD; Fourier transform infrared spectroscopy; fluorescence spectroscopy; proteaseinhibitor; proteins