The effect of 1-ethyl-3(3-dimethylaminopropyl)carbodiimide on calcium binding and associated changes in chloroplast structure and chlorophyll a fluorescence in spinach chloroplasts.
1. Chemical modification of carboxyl groups on the chloroplast membrane with a water-soluble carbodiimide plus a nucleophile caused inhibition of Ca-2plus binding. 2. Both binding sites were affected and showed a decrease in the number of binding sites and an increase in the dissociation constant. 3. Cation-induced changes in chlorophyll a fluorescence and structural changes (deltaA540) were inhibited at the same carbodiimide concentrations as Ca-2plus binding, emphasizing the relationship between these processes. 4. Chloroplasts that were illuminated with high intensity light for short time periods showed a decrease in the carbodiimide-mediated inhibition of Ca-2plus binding.
D002118:Calcium / Q000378:metabolism*; D002234:Carbodiimides / Q000494:pharmacology*; D002734:Chlorophyll / Q000378:metabolism*; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004237:Diuron / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D010944:Plants; D011955:Receptors, Drug; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
D002234:Carbodiimides; D011955:Receptors, Drug; D002734:Chlorophyll; D004024:Dicyclohexylcarbodiimide; D004237:Diuron; D002118:Calcium