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2. Mercury inhibits the activity of the NADPH:protochlorophyllide oxidoreductase (POR)

Creator:
Lenti, K., Fodor, F., and Böddi, B.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll formation, fluorescence emission spectra, heavy metal, Hg, protochlorophyllide, Triticum, and wheat
Language:
Multiple languages
Description:
The effect of Hg++ was studied on the arrangement and photoactivity of NADPH:protochlorophyllide oxidoreductase (POR) in homogenates of dark-grown wheat (Triticum aestivum L.) leaves. 77 K fluorescence emission spectra of the homogenates were recorded before and after the irradiation of the homogenates and the spectra were deconvoluted into Gaussian components. The mercury treatment caused a precipitation of the membrane particles, which was followed by a remarkable decrease of the fluorescence yield. 10-3 M Hg++ decreased the ratio of the 655 nm-emitting protochlorophyllide (Pchlide) form to the 633 nm-emitting form. 10-2 M Hg++ shifted the short wavelength band to 629-630 nm and a 655 nm form was observed which was inactive on irradiation. This inhibition may be caused by serious alteration of the enzyme structure resulting in the trans-localisation of NADPH within the active site of POR. and K. Lenti, F. Fodor, B. Böddi.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public