Ornithine Carbamoyltransferase from Spinacea oleracea: Purification and Characterization

Influences of temperature and threshold effect of NaCl concentration on Alpias vulpinus OCT

“…The enzyme was purified as described previously [16], with minor modification. Defrosted portions of shark liver were homogenized in a Potter homogenizer with 50 mM Tris-HCl (pH 7.8) containing 1 mM 2-mercaptoethanol.…”

“…The solution was maintained at that temperature for 1 min, then cooled in an ice bath and centrifuged at 13,000 × g for 10 min. The enzyme purification from supernatant was obtained by affinity chromatography according to Bellocco et al [16]. Enzyme purity was monitored by 10.5% SDS/PAGE electrophoresis according to Laemmli [17].…”

“…is a multimeric enzyme. It is a protein well preserved during evolution in different species [11][12][13][14]. The enzyme (M w 120,000) has a trimeric structure composed of identical subunits, catalyzes the synthesis of citrulline from ornithine and carbamoyl phosphate with the release of orthophosphate during the first step in the de novo biosynthesis of arginine [13].…”

Stabilization effects of kosmotrope systems on ornithine carbamoyltransferase

“…The enzyme was purified as described previously [8] with minor modification. 4 g of thresher shark (A. vulpinus) liver was homogenate with 1:4 (w/v) of Tris-HCl 50 mM pH 7.8 with 1 mM ␤-mercaptoethanol.…”

“…We have investigated the ornithine carbamoyltransferase (OCTase) which catalyzes the carbamoylation of l-ornithine to form citrulline in the sixth step of the arginine biosynthesis pathway [6][7][8]. OCTase has a trimeric structure composed of identical subunits and catalyzes the synthesis of citrulline from ornithine and carbamoyl phosphate with the release of orthophosphate during the first step in the de novo biosynthesis of arginine.…”