Arginase and

Iyer R et al The human arginases and arginase deficiency. J Inherit Metab Dis 1998 21 86. 

The importance of manganese for bacteria, such as that of Ni and to a lesser extent Co, as we saw in the last chapter, is considerable. Of course, as we will see shortly, it is also important in the tetranuclear Mn cluster that is involved in oxygen production in photosynthetic plants, algae and cyanobacteria, as well as in a number of mammalian enzymes such as arginase and mitochondrial superoxide dismutase. Most of manganese biochemistry can be explained on the one hand by its redox activity, and on the other by its analogy to Mg2+ (reviewed in Yocum and Pecoraro, 1999). 

Nau WM, Ghale G, Hennig A et al (2009) Substrate-selective supramolecular tandem assays monitoring enzyme inhibition of arginase and diamine oxidase by fluorescent dye displacement from calixarene and cucurbituril macrocycles. J Am Chem Soc 131 11558-11570... 

Arginine is capable of binding in the active site of PAH but it is not an enzyme substrate. Crystal structures of PAH from Streptomyces clavuligerus show that the metal binding site is very similar to that of arginase and the Mn—Mn distance is 3.3 A The main difference between arginase and PAH is in the binding pocket at the o-amino-terminus of the substrate. ... 

The complete urea cycle as it occurs in the mammalian liver requires five enzymes Argininosuccinate synthase, arginase, and argininosuccinate lyase (which function in the cytosol), and ornithine transcarbamoylase, and carbamoyl phosphate synthase (which function in the mitochondria). Additional specific transport proteins are required for the mitochondrial uptake of L-ornithine, NH3, and HC03 and for the release of L-citrulline. 

Figure 24 The first coordination spheres of Mn(II) in arginase and catalase.

Lambert, C. and Duranton, H., Effect of light on arginase and urease activities in Jerusalem artichoke tissues cultivated in vitro, C. R. Seances Acad. Sci. D, 270, 3217-3219, 1970. 

Fig. 5.15 demonstrates the results of the analysis of 17 protein amino acids. As Arg and His are acylated only with difficulty by this procedure, the authors recommended either decreasing the acidity by adding sodium or lithium carbonate or converting Arg into Orn with the aid of the enzyme arginase and His into aspartic acid by ozonolysis. 

Figure 13 Degradation of amino acids by arginase and threonine deaminase, defense proteins induced in tomato leaves after insect herbivory.

Meurs H, Maarsingh H, Zaagsma J. Arginase and asthma novel insights into nitric oxide homeostasis and airway hyperresponsiveness. Trends Pharmacol Sci 2003 24 450-5. 

AMP-sepharose suspension to the LDH solution. Both examples, arginase and lactate dehydrogenase monitoring, might be attractive in industrial scale purification of enzymes. 

The major role of manganese in biology is in oxygen production by photosynthetic plants, algae, and cyanobacteria. It is also involved in a number of mammalian enzymes like arginase and mitochondrial superoxide dismutase and it also plays an important role in microbial metabolism. Most of manganese biochemistry can be... 

The levels of arginase and argininosuccinate lyase were measured only in red blood cells in these cases. In one child, no detectable activity of arginase was found in the other only 12 of the mean normal level was found (Table 10). Lyase activity was normal in both children. The two enzyme activities were also measured in the parents, and both were found to be below the lowest level found in a series of normal controls, suggesting the heterozygote state. In both the lyase activity was normal. 

Hyperargininemia Levels op Arginase and Argininosuccinate Lyase IN Red Blood Cells ... 

The activities of the enzymes of the cycle estimated in a liver biopsy obtained at laparotomy from two of these children were found to be similar to those of control normals. Furthermore, the Km value for arginine of the liver arginase and the inhibition constant for L-lysine and L-ornithine were the same for the patient as those of the control subjects. This points to the fact that the hyperammonemia could not be explained on the basis of an abnormal arginase. There may still have been, however, a kinetic abnormality of one of the other four enzymes. 

For complete esterification of all amino acids, it is essential that absolutely dry reagents be used. Arginine and histidine also present some difficulties, but it is suggested that by conversion of arginine to ornithine (using arginase) and histidine to aspartic acid (by ozonolysis), these two amino acids can be satisfactorily analyzed quantitatively by the above procedure. 

Kuhn NJ, Ward S, Piponski M, et al. 1995. Purification of human hepatic arginase and its manganese (Il)-dependent and pH-dependent interconversion between active and inactive forms A possible pH sensing function of the enzyme on the ornithine cycle. Arch Biochem Biophys 320 24-34. 

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