41. Ornithine displaces the lysine to form a Schiff base attached to ODC, which decarboxylates to form a quinoid intermediate.42. Arginase is a binuclear manganese metallopritein that catalyse the hydrolysis of L-arginine to L-ornithine and urea. 43. The OAT involved in the ultimate formation of the non-essential amino acid proline from the amino acid ornithine . 44. It catalyzes the reverse reaction as well, and is therefore essential in creating ornithine from the starting substrate proline. 45. This gene encodes a taxon-specific crystallin protein that binds NADPH and has sequence similarity to bacterial ornithine cyclodeaminases. 46. A fourth protein located at the cell membrane acts as transporter, allowing the antiporter exchange between arginine and ornithine . 47. Likewise, defects in the enzymes responsible for the urea cycle, such as ornithine transcarbamylase, lead to hyperammonemia. 48. Most victims of the rare disorder-- known as ornithine transcarbamylase deficiency, or OTC-- die as infants. 49. The actual reaction catalyzed by AGAT is the synthesis of guanidinoacetate from arginine and glycine, with ornithine as a byproduct. 50. The metabolic pathways : lysine degradation, arginine and proline metabolism, and d-arginine and d-ornithine metabolism.
