Dual uric acid

In conclusion, the enzymic machinery of the bird is modulated in such a fashion that glutamate is converted to glutamine which will carry the NH2 with it in a straight-forward excretory pathway for uric acid. While in the mammal, the glutamine plays a dual role the major portion is split and the NH2 is used to form urea, a smaller portion enters the purine biosynthetic pathway and the activity of the key enzyme involved is delicately regulated by allosteric mechanisms. 

Kasai, S., Hirano, Y, Motochi, N., Shiku, H., Nishizawa, M., Matsue, T. Simultaneous detection of uric acid and glucose on a dual-enzyme chip using scanning electrochemical microscopy/scanning chemiluminescence microscopy. Anal Chim Acta 2002, 458, 263-270. 

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