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...

The inhibition of succinate oxidation by malonate is a well known phenomenon. Since the oxidation of succinate to fumarate is an integral part of the Krebs cycle of oxidations, it has been generally assumed that the inhibitory effect of malonate upon the oxidation of any member of the cycle is the result of the inhibition of the succinate to fumarate step. However, the present paper provides ev...

Is there tight channelling in the tricarboxylic acid cycle metabolon? Balazs Sumegi,§ A. Dean Sherry,§ Craig R. Malloy,*$ Claudia Evans*t and Paul A. Srere*t *Pre-Clinical Science Unit of the Department of Veterans Affairs Medical Center, tDepartment of Biochemistry and $The Mary Nell & Ralph B. Rogers N.M.R. Center, The University of Texas Southwestern Medical Center at Dallas, 4500 South Lanc...

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 ...

Wrede and Rothhaas (1934) proposed a tripyrrylmethene structure for the red pigment extracted from Serratia marcescens. This structure was supported by Hubbard and Rimington (1950) because of the similarity in spectral properties between extracted pigment and a synthetic tripyrrylmethene compound. Recent investigations (Williams et al., 1956) have demonstrated that pigment identical in spectral...

BACKGROUND Although myocardial oxidative tricarboxylic acid (TCA) cycle activity and contractile function are closely linked in normal cardiac muscle, their relation during postischemic reperfusion, when contractility often is reduced, is not well defined. METHODS AND RESULTS To test the hypothesis that oxidative TCA cycle flux is reduced in reperfused myocardium with persistent contractile d...

Carboxylic acids are Brønsted-Lowry acids, they are proton donors. They are the most common type of organic acid. Among the simplest examples are the formic acid H-COOH, that occurs in ants, and acetic acid H3C-COOH group, that gives vinegar its sour taste. Acids with two or more carboxyl groups are called dicarboxylic, tricarboxylic, etc. The simplest dicarboxylic example is oxalic acid (COOH)...