Open AccessREGULATORY EFFECTS OF SUBSTRATES ON A PHOSPHOTRANSFERASE FROM Aerobacter aerogenes AND THE MODIFICATION OF ITS ACTIVITY BY PARTIAL PROTEOLYSIS
Author(s) -
S. Schaefler,
Isaac Schenkein
Publication year - 1969
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.62.4.1210
Subject(s) - chemistry , enzyme , biochemistry , phosphotransferase , enterobacter aerogenes , pep group translocation , fructose 1,6 bisphosphatase , fructose , glucosamine , phosphoenolpyruvate carboxykinase , escherichia coli , gene
An enzyme isolated fromAerobacter aerogenes acts both as phosphomonoesterase and phosphotransferase with glucose, glucosides, glucosamine, and N-acetyl glucosamine as acceptors. When glucose-6-phosphate is the phosphate donor, these acceptors appear to act as activators of the enzyme, while withp -nitrophenyl phosphate, α-glycerophosphate, fructose-1,6-diphosphate, and several other phosphate esters as donors, the same acceptors act as noncompetitive inhibitors. Withp -nitrophenyl phosphate as the phosphate donor, no inhibition is observed when glucose is replaced as acceptor by 2-deoxy glucose. The inhibition by glucose and other acceptors is eliminated at low pH or by increasing the temperature of reaction. Partial proteolysis of the enzyme by chymotrypsin produces a modified enzyme (gl-phosphotransferase-Ch) that shows altered relative velocities for the hydrolysis of several substrates as well as altered regulatory effects by acceptors.