A glucokinase-like-enzyme in the liver of Atlantic salmon (Salmo salar).
An enzyme with properties similar to rat liver glucokinase (Hexokinase IV or D) is present in salmon liver in addition to low-Km hexokinase(s). The specific activity of this enzyme increases about 1.6 fold, comparing activities after feeding diets with 25% and 0% digestive energy from starch. The enzyme has a low affinity for glucose, S0.5 = 25.2-26.8 mM (95% confidence interval) and a low activity with fructose, approximately 8% of the activity with glucose. Its molecular mass was estimated to 50.7 +/- 0.6 kDa (SEM. n = 3) by gel filtration, and it displays positive cooperativity with respect to glucose. The Hill constant = 1.73-1.81 (95% confidence interval). The enzyme is competitively inhibited by N-acetyl glucosamine, K(i) approximately 0.28 mM.
Tranulis
M A
MA
Department of Biochemistry, Physiology and Nutrition, Norwegian College of Veterinary Medicine, Oslo, Norway.
Dregni
O
O
Christophersen
B
B
Krogdahl
A
A
Borrebaek
B
B
D000117:Acetylglucosamine / Q000494:pharmacology; D000818:Animals; D001667:Binding, Competitive; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005941:Glucokinase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D042843:Glucose 1-Dehydrogenase; D005948:Glucose Dehydrogenases / Q000737:chemistry / Q000378:metabolism; D006003:Glycogen / Q000032:analysis / Q000378:metabolism; D006593:Hexokinase / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000737:chemistry / Q000201:enzymology*; D008970:Molecular Weight; D012474:Salmon / Q000378:metabolism*
D004791:Enzyme Inhibitors; D006003:Glycogen; D005948:Glucose Dehydrogenases; D042843:Glucose 1-Dehydrogenase; D006593:Hexokinase; D005941:Glucokinase; D005947:Glucose; D000117:Acetylglucosamine