Stimulation of spinach (Spinacia oleracea) chloroplast fructose‐1,6‐bisphosphatase by mercuric ions

摘要

>Chloroplast fructose-1,6-bisphosphatase can exist in an active reduced form or a less active oxidised form. Oxidised fructose bisphosphatase from spinach (Spinacia oleracea) could be stimulated up to many hundred-fold by 0.1 mM HgCl₂ whereas fructose bisphosphatases from rabbit, yeast, a non-chloroplast enzyme from spinach and the reduced chloroplast enzyme were only inhibited by HgCl₂. Stimulation of the enzyme was maximal at pH 8.0 and low magnesium concentrations where the oxidised enzyme normally has little activity.