Chemical modification of plastocyanin with 7 chloro 4 nitrobenz 2 oxa 1 3 diazole preparation and characterization
Wang, M.Y.; Tsai, M.Yu; Pan, R.L.; Gross, E.L.
Botanical Bulletin of Academia Sinica (Taipei) 30(1): 59-70
1989
Accession: 007107038
Spinach plastocyanin was modified by 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD-Cl) whose alkylamine derivative was fluorescent. The Vmax for electron transport from plastocyanin to P700+ was decreased by 30% after modification. The Km for P700+ reduction was also decreased from 15 .mu.M to 5 .mu.M. Meanwhile, the modification increased 10mV more positive of redox potential. The absorption (A480) and fluorescence (F550) of NBD-plastocyanin were investigated as a probe to study its conformational change against environment. The major labelled group on plastocyanin was identified as lysine-54.