[Effects of starvation, a hyperprotein diet and treatment with nicotinamide on L-threonine aldolase and allothreonine aldolase in the rat liver].
In order to evaluate if the aminoacid L-threonine and its isomer allothreonine are metabolized by a single protein or by two specific enzymatic proteins, in the rat liver, we have studied the behaviour of L-threonine aldolase activity and allothreonine aldolase activity in rats which are injected with nicotinamide (1 g/ Kg) or have received a special diet containing 91% of casein or that have been starved for several days. The L-threonine aldolase enhances its activity in all three cases, while the allothreonine aldolase does not show significative changes of activity. These different behaviours of the two enzymatic activities, support the hypothesis that in the rat liver two proteins are necessary for the metabolism of the L-threonine and its isomer allothreonine.
D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D012696:Glycine Hydroxymethyltransferase / Q000378:metabolism*; D007536:Isomerism; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D009536:Niacinamide / Q000494:pharmacology*; D051381:Rats; D013217:Starvation / Q000201:enzymology*; D013912:Threonine / Q000378:metabolism; D014166:Transferases / Q000378:metabolism*
D004044:Dietary Proteins; D009536:Niacinamide; D013912:Threonine; D014166:Transferases; D012696:Glycine Hydroxymethyltransferase
Effetti del digiuno, della dieta iperproteica e del trattamento con nicotinamide sulla L-treonina aldolasi e sulla allotreonina aldolasi di fegato di ratto.