DEGRADATION OF PHOTOSYSTEM-II REACTION-CENTER D1-PROTEIN INDUCED BY UVB RADIATION IN ISOLATED THYLAKOIDS - IDENTIFICATION AND CHARACTERIZATION OF C-TERMINAL AND N-TERMINAL BREAKDOWN PRODUCTS
G. Friso et al., DEGRADATION OF PHOTOSYSTEM-II REACTION-CENTER D1-PROTEIN INDUCED BY UVB RADIATION IN ISOLATED THYLAKOIDS - IDENTIFICATION AND CHARACTERIZATION OF C-TERMINAL AND N-TERMINAL BREAKDOWN PRODUCTS, Biochimica et biophysica acta. Bioenergetics, 1184(1), 1994, pp. 78-84
The effects of UVB radiation on the stability of Photosystem II reacti
on center D1-protein in isolated thylakoids are investigated. A new C-
terminal degradation product has been identified and characterized, pr
oduced by cleavage in the second transmembrane segment. Immunological
evidence for the presence of N-terminal fragments corresponding to the
remaining part of D1-protein is also provided. The appearance of thes
e fragments is not affected by lowering the temperature from 22 degree
s C to 4 degrees C, changing the pH from 6 to 8, adding soybean trypsi
n inhibitor or excluding oxygen from the thylakoid suspension.