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Isolation And Characterization Of The Tricarboxylate Transporter From Pea Mitochondria, Cecilia A. Mcintosh, David J. Oliver
Isolation And Characterization Of The Tricarboxylate Transporter From Pea Mitochondria, Cecilia A. Mcintosh, David J. Oliver
David J. Oliver
The tricarboxylate transporter was solubilized from pea (Pisum sativum) mitochondria with Triton X-114, partially purified over a hydroxylapatite column, and reconstituted in phospholipid vesicles. The proteoliposomes exchanged external [14C]citrate for internal citrate or malate but not for preloaded D,L-isocitrate. Similarly, although external malate, succinate, and citrate competed with [14C]citrate in the exchange reaction, D,L-isocitrate and phosphoenolpyruvate did not. This tricarboxylate transporter differed from the equivalent activity from animal tissues in that it did not transport isocitrate and phosphoenolpyruvate. In addition, tricarboxylate transport in isolated plant mitochondria, as well as that measured with the partially purified and reconstituted transporter, was less …
Nad+-Linked Isocitrate Dehydrogenase: Isolation, Purification, And Characterization Of The Protein From Pea Mitochondria, Cecilia A. Mcintosh, David J. Oliver
Nad+-Linked Isocitrate Dehydrogenase: Isolation, Purification, And Characterization Of The Protein From Pea Mitochondria, Cecilia A. Mcintosh, David J. Oliver
David J. Oliver
The NAD+-dependent isocitrate dehydrogenase from etiolated pea (Pisum sativum L.) mitochondria was purified more than 200-fold by dye-ligand binding on Matrix Gel Blue A and gel filtration on Superose 6. The enzyme was stabilized during purification by the inclusion of 20% glycerol. In crude matrix extracts, the enzyme activity eluted from Superose 6 with apparent molecular masses of 1400 ± 200, 690 ± 90, and 300 ± 50 kD. During subsequent purification steps the larger molecular mass species disappeared and an additional peak at 94 ± 16 kD was evident. The monomer for the enzyme was tentatively identified at 47 …
H-Protein Of The Glycine Decarboxylase Multienzyme Complex: Complementary Dna Encoding The Protein From Arabidopsis Thaliana, David J. Oliver
H-Protein Of The Glycine Decarboxylase Multienzyme Complex: Complementary Dna Encoding The Protein From Arabidopsis Thaliana, David J. Oliver
David J. Oliver
The glycine decarboxylase multienzyme complex is composed of four component enzymes, the 100-kD P-protein (a pyridoxal 5-phosphate-dependent amino acid decarboxylase), the 14-kD H-protein (a lipoamide-containing carrier protein), the 45-kD T-protein (a tetrahydrofolate transferase), and the 59-kD L-protein (lipoamide dehydrogenase) (5). The Iipoamide cofactor of the H-protein carries reaction intermediates between the active sites of the other three component proteins. These proteins form a large molecular weight complex (4) within the matrix ofleaf mitochondria where, together with the enzyme serine hydroxymethyltransferase, it catalyzes the photorespiratory conversion of two molecules of glycine to one each of serine, NH3, and CO2 with the …