Coenzyme A synthesis

Table 4.10 Summary of reaction metrics and synthesis tree parameters for coenzyme-A synthesis plans ranked according to overall kernel (maximum) RME. ...

This is followed by removal of the glutamic acid and the glycine residues, which is followed by acetylation of the remaining cysteine. Essential amino acids are required for the synthesis of the proteins involved, pantothenic acid for coenzyme A synthesis, and phosphorus for synthesis of the ATP needed for glutathione synthesis. Similar scenarios can be developed for glucuronide and sulfate formation, acetylation, and other phase II reaction systems. 

Review Problem 1 6 Design for TM204, an intermediate in Coenzyme A Synthesis,... 

The liver meets the larger part (60%) of its requirement for cholesterol by synthesis de novo from acetyl-coenzyme A. Synthesis rate is regulated at the step leading from hydroxymethylglutaryl-CoA (HMG-CoA) to mevalonic acid (p.l61A), with HMG-CoA reductase as the rate-limiting enzyme. 

Robishaw JD, Berkich D, and Neely JR (1982) Rate-limiting step and control of coenzyme A synthesis in cardiac muscle. Journal of Biological Chemistry 257, 10967-72. 

Barondeau, D. P., and Lindahl, P. A., 1997, Methylation of carbon monoxide dehydrogenase from Clostridium thermoaceticum and mechanism of acetyl coenzyme A synthesis, J. Am. Chem. Soc. 119(17) 3959n3970. 

Rieke E, Barry S, Mosbach K. N6-N-(6-Aminohexyl)Carbamoyl-methyl-Coenzyme-A-synthesis and application in affinity chromatography and as an immobilized active coenzyme. Euro. J. Biochem. 1979 100 203-212. 

The serum level of pantothenic add is about 1 to 5 lM (Lopaschuk d ai, 1987). The vitamin in the bloodstream is transported into various tissues, where it is then converted to coenzyme A. Coenzyme A is synthesized from pantothenic add, ATP, and cysteine. The pathway of coenzyme A synthesis is shown in Figure 9,77. The cofactor of fatty add synthase is synthesized from coenzyme A and does not involve the direct participation of pantothenic acid. A specific enzyme catalyzes... 

Harder SR, Lu W-P, Freiberg BA, Ragsdale SW (1989) Spectroelectrochemical studies of corri-noid iron-sulfur protein involved in acetyl coenzyme-A synthesis by Clostridium thermoace-ticum. Biochemistry 28 9080-9087... 

The direct route of acyl coenzyme A synthesis from a free carboxylic acid is catalysed by a group of nucleoside triphosphate-requiring en mes, collectively known as thiokinases. The general mechanism, as exemplified for acetate activation by acetyl thiokinase, proceeds as follows. The carboxylic acid is first activated by acetyl adenylate formation with the displacement of pyrophosphate from ATP. While the initial reaction is fully reversible, subsequent action of pyrophosphatase drives the reaction... 

Furthermore it was possible to demonstrate the presence in the intestine of all the enzymes required for these steps. Fatty acid-coenzyme A synthesis was demonstrated by Ailhatjd et al. (1962) and by Clark and Hubscher (1960). The involvement of phosphatidic acid could be demonstrated by isolation of radioactive phosphatidic acid in intestinal preparations incubated with radioactive fatty acids or phosphoric acid (Johnston and Bearden 1960). Furthermore, a significant dilution effect in the synthesis of glycerides from C-fatty acids occurred by the addition of phosphatidic acid (Clark and Hubscher 1961). Phosphatichc acid phosphatase activity in the intestine was reported by Coleman and Hubscher (1962) and by Johnston and Bearden (1962). Finally, the conversion of diglyceride into triglycerides by the addition of a fatty acid — Co A was shown to take place in the intestine by Clark and Hubscher (1961). 

Treede H.J., Riens B. and Heise K.P., 1986. Species-specific differences in acetyl coenzyme A synthesis of chloroplasts. Z. Naturforsch. 41c, 733-740 Uchiyama M., Washio N., Ikar T., Igarashi H. and Suzuki I., 1986. Stereospecific responses to (R)-(+)-and (S)-(-)-quizalofop-ethyl in tissues of several plants. J. Pesticide Sci 459-467. 

REGULATION OF ACETYL COENZYME A SYNTHESIS IN CHLC OPLASTS... 

CODH can bring about two reactions (e.g., Eq. 16.26 and Eq. 16.28) of particular organometallic interest the reduction of atmospheric CO2 to CO (CODH reaction, Eq. 16.26) and acetyl coenzyme A synthesis (ACS reaction, Eq. 16.28) from CO, a CH3 group possibly taken from a corrinoid iron-sulfur protein (denoted CoFeSP in the equation), and coenzyme A, a thiol. Tliese are analogous to reactions we have seen earlier the water-gas shift reaction (Eq. 16.25) and the Monsanto acetic acid process (Eq. 16.27). 

Roberts, J.R., Lu, W.P., Ragsdale, S.W., 1992. Acetyl-coenzyme-A synthesis from methylte-trahydrofolate, CO, and coenzyme-A by enzymes purified from clostridium-thermoaceticum — attainment of invivo rates and identification of rate-limiting steps. Journal of Bacteriology 174 (14), 4667—4676. 

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