Kinetic studies on muscle glycogen synthase.
Using the I form of rabbit muscle glycogen synthase essentially free of glycogen, the kinetics and mechanism of action was investigated. No evidence for an exchange between [14C]UDP and UDP-glucose was found. The bisubstrate kinetics of the enzyme for UDP-glucose and glycogen, as well as for UDP-glucose and maltose, was determined. An intersecting pattern in the double reciprocal plot (velocity versus substrate concentration) suggestive of a sequential mechanism (ordered or random) was found in all cases. The K-m for UDP-glucose (45 to 48 mM) was the same with either maltose or glycogen as acceptor. The K-m for maltose (230 mM) and for glycogen (1.5 mug/ml) differed.
D000818:Animals; D005990:Glycerol / Q000494:pharmacology; D006003:Glycogen; D006006:Glycogen Synthase / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008320:Maltose; D009132:Muscles / Q000201:enzymology*; D011189:Potassium Chloride / Q000494:pharmacology; D011487:Protein Conformation; D011817:Rabbits; D014532:Uridine Diphosphate Glucose / Q000378:metabolism
D011189:Potassium Chloride; D008320:Maltose; D006003:Glycogen; D006006:Glycogen Synthase; D005990:Glycerol; D014532:Uridine Diphosphate Glucose