Concerted Feedback Inhibition

Concerted Feedback Inhibition

Concerted feedback inhibition of aspartokinase activity from Pseudomonasfluorescens by the combination of L-threonine and r.-lysine, or by L-threonine and L-methionine was freely and rapidly reversible. Inhibition by L-threonine, or by the concerted pairs of amino acids was kinetically “mixed” with respect to L-aspartate and noncompetitive with regard to ATP. In the presence of L-threonine the ...

Concerted Feedback Inhibition MODIFIER - INDUCED OLIGOMERIZATION OF THE PXEUDOMONAX

Concerted feedback inhibition of aspartokinase activity from Pseudomonasfluorescens by the combination of L-threonine and r.-lysine, or by L-threonine and L-methionine was freely and rapidly reversible. Inhibition by L-threonine, or by the concerted pairs of amino acids was kinetically “mixed” with respect to L-aspartate and noncompetitive with regard to ATP. In the presence of L-threonine the ...

Concerted feedback inhibition. Purification and some properties of aspartokinase from Pseudomonas fluorescens.

Aspartokinase of Pseudomonas fluorescens has been purified by heat treatment, ammonium sulfate fractionation, DEAE-cellulose chromatography, and by successive gel filtration steps on Sephadex G-ZOO in the presence and absence of feedback modifiers. The 700-fold purified enzyme was judged to be greater than 90% pure. Sedimentation velocity centrifugation yielded an a~,,+, value of 6.7 S, a Dw,.~...

Feedback inhibition of nitrogenase.

No inhibition of nitrogenase activity by physiological levels of NH4+ or carbamyl phosphate was observed in extracts of Azotobacter vinelandii. All of the 15N2 reduced by cultures which received no NH4+ was found in the cells. By contrast, more than 95% of the 15N2 reduced by cultures which had been given NH4+ was found in the medium. Failure to examine the culture medium would lead to the erro...

Selective inhibition of glycosidases by feedback prodrugs.