Open AccessQuaternary Structure of Higher Plant Glyceraldehyde‐3‐Phosphate Dehydrogenases
Author(s) -
CERFF Rüdiger
Publication year - 1979
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1979.tb12891.x
Subject(s) - spinacia , tetramer , pisum , hordeum vulgare , dehydrogenase , biochemistry , ammonium sulfate precipitation , nad+ kinase , biology , spinach , glyceraldehyde 3 phosphate dehydrogenase , protein subunit , isozyme , affinity chromatography , glyceraldehyde , protein quaternary structure , enzyme , size exclusion chromatography , botany , chloroplast , poaceae , gene
1 NAD(P) + ‐induced changes in the aggregational state of prepurified NADP‐linked glyceraldehyde‐3‐phosphate dehydrogenase (EC 1.2.1.13) were used to isolate the enzyme from Spinacia oleracea, Pisum sativum and Hordeum vulgare . Each of the three plant species contains two separate isoenzymes. Isoenzyme 1 (fast moving during conventional electrophoresis) precipitates with the ammonium sulfate fraction 55–70% saturation. It shows two separate subunits in dodecylsulfate gels, which are probably arranged as A 2 B 2 in the native enzyme molecule. Isoenzyme 2 (slow moving during conventional electrophoresis) precipitates with the ammonium sulfate fraction 70–95%. It contains a single subunit of the same M r as subunit A in isoenzyme 1 and is apparently a tetramer (A 4 ). The molecular weights of subunits A/B for spinach, peas and barley were determined as 38000/40000, 38000/42000 and 36000/39000 respectively. 2 The NAD‐specific glyceraldehyde‐3‐phosphate dehydrogenase (EC 1.2.1.12) was purified from Spinacia oleracea and Pisum sativum by affinity chromatography on blue Sepharose CL‐6B. The enzyme from both plant species is shown to be a tetramer of subunits with M r 39000. 3 The present findings contrast with heterogeneous results obtained previously by other authors. These results suggested that there are considerable interspecific differences in the quaternary structure of glyceraldehyde‐3‐phosphate dehydrogenases from higher plants.