PMID: 41601Oct 1, 1979

Comparative kinetic properties of structure-bound and solubilized L-threonine dehydratase from brewer's yeast

Biokhimii︠a︡
S V KovalevaZ S Kagan

Abstract

It has been shown that L-threonine dehydratase (EC 4.2.1.16) of brewer's yeast Saccharomyces carlsbergensis is localized in the mitochondrial fraction. The enzyme is easily solubilized from the mitochondria by changing the pH and ionic strength of the buffer. Some kinetic properties of structure-bound and solubilized L-threonine dehydratase have been compared at pH 6,5. The kinetic plots of the initial rate of the reaction versus initial substrate concentration for both enzymes have a hyperbolic shape; the affinities of both enzymes for the substrate appear to be similar (Km = 20 mM). Both enzymes are inhibited by L-isoleucine, the shape of the kinetic plots being thereby changed into sigmoidal. Solubilization results in a decrease of the mitochondral enzyme sensitivity to the inhibition by L-isoleucine and in an appearance of cooperative interactions between the allosteric sites.

Related Concepts

Allosteric Site
Enzymes, antithrombotic
Threonine Dehydratase
Lyase
Saccharomyces
Mitochondria
Enzymes for Treatment of Wounds and Ulcers
Metabolic Inhibition
Isoleucine
Enzymes, hematological

Related Feeds

Biosynthetic Transformations

Biosyntheic transformtions are multi-step, enzyme-catalyzed processes where substrates are converted into more complex products in living organisms. Simple compounds are modified, converted into other compounds, or joined together to form macromolecules. Discover the latest research on biosynthetic transformations here.