Arginine synthesis

An anomaly associated with citrulline that became evident when detailed kinetic studies were made in the 1950s (R.B. Fisher and J.R. Bronk) was the irreproducibility of its catalytic activity in liver slices on the formation of urea, despite the clear evidence from Ratner and Petrack of its importance in arginine synthesis. Initially the discrepancy in catalytic activity between ornithine and citrulline was ascribed to the possible impermeability of the liver cell plasma membrane to the latter intermediate, a hypothesis which was rapidly disproved experimentally. Only recently has it been shown that ornithine transcarbamylase is clearly associated with the ornithine/... 

Baich, A. Vogel, H.J. N-Acetyl-y-glutamokinase and N-acetylglutamic y-semialdehyde dehydrogenase repressible enzymes of arginine synthesis in Escherichia coh. Biochem. Biophys. Res. Commun., 7, 491-496 (1962)... 

G. Wu and C. J. Meininger, Regulation of L-arginine synthesis from L-citrulline by L-glutamine in endothelial cells. Am J Physiol 265, H1965-H1971 (1993). 

R6. Ratner, S., and Pappas, A., Biosynthesis of urea Part 1. Enzymatic mechanism of arginine synthesis from citrulline. J. Biol. Chem. 179, 1183-1198 (1949). 

Glutamate is also a precursor of arginine. Arginine synthesis begins with the acetylation of the a-amino group of glutamate. N-acetylglutamate is then... 

Proline is synthesized from glutamate in three steps. The second step is a spontaneous cyclization reaction. In arginine synthesis the acetylation of glutamate prevents the cyclization reaction. In mammals the reactions that convert ornithine to arginine are part of the urea cycle. 

Urea cycle and arginine synthesis. The general aspect and control of the urea synthesis and the role of the intestine and kidney in arginine synthesis are shown above. 

The major tissues involved in net arginine synthesis from glutamate for body protein synthesis are... 

Arginine Synthesis, Proline Synthesis, and Related Processes... 

Fig. 3. Proline and arginine synthesis and degradation to show interrelationships between the pathways. The structures are glutamic acid (GLU), ornithine (ORN), citrulline (CIT), arginine (ARG), urea. 2-oxo-5-amino valeric acid (OAV), A -pyrroline-2-carboxylic acid (P2C), proline (PRO), A -pyrroline-5-carboxylic acid (P5C), glutamic semialdehyde (GSA).

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