Porphyrin biosynthesis in the soybean callus system-XVII. Effect of monovalent and divalent cations on the activity of succinyl CoA synthetase
1. 1. The effect on the activity of soybean callus Succinyl CoA Synthetase of EDTA, 8-OH quinoline, o-phenantroline, α,α $ ́dipyridyl, sodium azide and sodium cyanide was assayed. EDTA completely inhibit the enzyme, cyanide only diminished its activity 30%, and the other compounds significantly enha...
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| Autores principales: | , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_0020711X_v12_n5-6_p717_DeXifra |
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| Sumario: | 1. 1. The effect on the activity of soybean callus Succinyl CoA Synthetase of EDTA, 8-OH quinoline, o-phenantroline, α,α $ ́dipyridyl, sodium azide and sodium cyanide was assayed. EDTA completely inhibit the enzyme, cyanide only diminished its activity 30%, and the other compounds significantly enhanced Succinyl CoA Synthetase activity. 2. 2. The action of various divalent cation chlorides was studied. The enzyme activation capacities of Mn2+ and Mg2+ were rather similar at all concentrations tested. At 4 and 5 mM Co2+ activates the enzyme more than Mg2+ and Mn2+. Complete inactivation was produced by Pb2+and Hg2+ at concentrations as low as 1 mM. Ca2+, Zn2+, Fe2+ and Cd2+ could not replace Mg2+ either, instead they inhibited Succinyl CoA Synthetase. 3. 3. The assay with the monovalent cations chlorides K +, NH+ 4, Na+ and Li+ showed that maximum activation for the first three was found at 50-60 mM while Li+ had no effect. Increasing concentrations of these cations progressivey progressively inhibited enzyme activity. © 1980. |
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