Mobilization and Catabolism

Glycerol may be picked up by liver and converted to dihydroxyacetone phosphate (DHAP) for gluconeogenesis, and the fetty adds are distributed to tissues that can use them. Free fatty acids are transported through the blood in association with serum albumin. 

Carnitine acyltransfefase-I (CAT-1) and carnitine acyltran erase-2 (CAT-2) are also refened to as carnitine palmrtoyl transferase-1 (CPT-1) and carnitine palmitoyl transferase-2 (CPT-2). The carnitine transport system is most important for allowing long-chain fatty acids to enter into the mitochondria. 

Fatty acids are oxidized in several tissues, including liver, muscle, and adipose tissue, by the pathway of P-oxidation. Neither erythrocytes nor brain can use fatty acids, and so continue to rely on glucose during normal periods of fastii. Erythrocytes lack mitochondria, and fatty acids do not cross the blood-hrain barrier efficiently. 

Carnitine acjdtransferase-l is inhibited by malonyl CoA from fetty add synthesis and thereby prevents newly synthesized fetty adds from entering the mitochondria. Insulin indirecdy inhibits P-oxidation by activating acetyl CoA carboxylase (fetty add synthesis) and increasing the malonyl CoA concentration in the cytoplasm. Glucagon reverses this process. 

The FADHj and NADH are oxidized in the electron transport chain, providing ATP. In musde and adipose tissue, the acetyl CoA enters the citric acid cyde. In liver, the ATP may be used for gluconeogenesis, and the acetyl CoA (which cannot be converted to glucose) stimulates gluco-neogenesis by activating pyruvate carboxylase. 

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Carbohydrate metabolism the involvement of Mn(II) with key enzymes of glucose storage, mobilization, and catabolic and anabolic metabolism is now well established. Effects at the cell, organ, and whole organism levels are less well understood, especially those related to interaction of Mn(II) with hormonal systems and receptors. 

Studies designed to test the mobilization and persistence of recombinant catabolic plasmid pDlO. 

Excess acetate (C2) can be converted to the mobile ketone body energy source aceto-acetate (C4) and thence its reduced form hydroxybutyrate (C,) for transport throughout the body. Excess acetate can be carboxylated (via acetylCoA carboxylase) to form malonylCoA (C3), the donor for further C2 additions (with C02 elimination) in the anabolic synthesis of long chain fatty acids. Fatty acids are components of the phospholipids of cellular membranes and are also stored as triacylglycerols (triglycerides) for subsequent hydrolysis and catabolic fatty acid oxidation to yield reduced coenzymes and thence ATP (see Chapter 2). 

Whereas RNA and protein synthesis in embryonic axes precedes and accompanies cell enlargement, division and differentiation, the development of enzymatic activity in storage organs occurs in the absence of such changes. Protein and RNA metabolism in storage organs is nevertheless a complex process, for synthesis and/or activation of hydrolytic enzymes to mobilize and modify reserves is accompanied by catabolism of other (stored) protein and RNA. For an account of those events associated with reserve degradation and hydro-... 

From the foregoing data It appears that low temperature enhances the anabolic processes concerned with mobilization and synthesis whereas the higher temperature accelerates oxidative and catabolic utilization of substances. 

As mentioned, several metabolites of lipoate have been isolated from cultures of P. putida LP. " Procedures have involved the use of [ C]lipoate labeled in positions 1 and 6 or 7 and 8 as source of C and S during growth, followed by solvent extractions and hydrophobic gel filtration or anion-exchange chromatographies of the culture supernatants. Purified compounds were characterized by chromatographic mobilities and spray reactions and by UV, IR, PMR, and mass spectrometries. When appropriate, comparisons were made with synthetic lipoic acid, the bisnor and tetranor analogs, and their thiol-sulfinates. ° A flow scheme of lipoate catabolism based on compounds isolated (structures), as well as inferred (names in brackets), is shown below. 

Daily, the two enzymes have quite distinct electrophoretic mobilities and immunological properties. Levels of leaf urease were calculated to be adequate for known flux rates for ureide metabolism. Polacco et al. (1985) speculated that this ubiquitous urease might play a role in ureide catabolism. 

Top EM, Springael D, Boon N (2002) Catabolic mobile genetic elements and their potential use in bioremediation of polluted soils and waters. FEMS Microbiol Ecol 42 199-208... 

Additionally, a further study described an increased catabolism and mobilization of vitamin A in the whole body (Kelley et al, 1998). 

Hill, K. E.,Fry, J. C. Weightman, A. J. (1994). Gene transfer in the aquatic environment persistance and mobilization of the catabolic recombinant plasmid pDIO in the epilithon. Microbiology, 140, 1555-63-... 

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