Diffusion of Tricarboxylic Acid Cycle Enzymes in the Mitochondrial Matrix in Vivo

Diffusion of tricarboxylic acid cycle enzymes in the mitochondrial matrix in vivo. Evidence for restricted mobility of a multienzyme complex.

It has been proposed that enzymes in many metabolic pathways, including the tricarboxylic acid cycle in the mitochondrial matrix, are physically associated to facilitate substrate channeling and overcome diffusive barriers. We have used fluorescence recovery after photobleaching to measure the diffusional mobilities of chimeras consisting of green fluorescent protein (GFP) fused to the C termin...

Intracellular distribution of tricarboxylic acid cycle enzymes in Azotobacter vinelandii.

The cytological complexity of the bacterial cell is well established, but little information is as yet available on the association of metabolic function with cellular structure in microorganisms. The significance of the tricarboxylic acid (TCA) cycle and the electron transport system in the metabolism of the obligate aerobic azotobacter cell makes important a knowledge of the intracellular dis...

Tricarboxylic acid cycle enzymes of the ectomycorrhizal basidiomycete, Suillus bovinus.

In crude cell extracts of the ectomycorrhizal fungus, Suillus bovinus, activities of citrate synthase, aconitase, isocitrate dehydrogenase, succinate dehydrogenase, fumarase, and malate dehydrogenase have been proved and analyzed. Citrate synthase exhibited high affinities for both its substrates: oxaloacetate (Km = 0.018 mM) and acetyl-CoA (Km = 0.014 mM). Aconitase showed better affinity for ...

Tricarboxylic Acid Cycle in

The Tricarboxylic Acid Cycle in Dictyostelium discoideum

Some aspects of tricarboxylic acid-cycle activity during differentiation and aging in Dictyostelium discoideum were examined. The concentrations of glutamate, aspartate, alanine, citrate, 2-oxoglutarate, succinate, fumarate, malate, oxaloacetate, pyruvate and acetyl-CoA were determined at four stages over the course of differentiation. The rate of 02 utilization was also determined over differe...