Yeast alpha-isopropylmalate isomerase. Factors affecting stability and enzyme activity.
نویسندگان
چکیده
منابع مشابه
Yeast alpha-isopropylmalate isomerase. Factors affecting stability and enzyme activity.
Yeast alpha-isopropylmalate isomerase was found to be markedly stabilized by high concentrations of glycerol and (NH4)2SO4. Such conditions of high ionic strength inhibited the enzyme, stabilized the enzyme to heat, and affected kinetic parameters. The isomerase was found to exhibit ionic strength-dependent hysteresis when enzyme, totally but reversibly inhibited by storage under conditions of ...
متن کاملPurification of yeast alpha-isopropylmalate isomerase. High ionic strength hydrophobic chromatography.
alpha-Isopropylmalate isomerase, the second enzyme specific for leucine biosynthesis, can be purified from extracts of yeast utilizing a chromatographic procedure that allows separation of proteins in the presence of high concentrations of (NH4)2SO4. The purification procedure utilizes the stabilizing effect of glycerol and (NH4)2SO4 on the isomerase and their opposing effects on protein retent...
متن کاملA Herbicidal Inhibitor of Isopropylmalate Isomerase
N itronate com pounds resembling the aa-carboxylate reaction interm ediate in the reaction catalyzed by isopropylm alate isomerase were investigated as enzyme inhibitors and potential herbicides. The nitronic acids o f l-hydroxy-2-nitrocyclopentane-l-carboxylic acid, nitroisop ropylm alate and o f l-hydroxy-2-nitrocyclohexane-l-carboxylic acid were all po ten t inhibi tors o f isopropylm alate...
متن کاملRegulation of isopropylmalate isomerase synthesis in Neurospora crassa.
The capacity to synthetize isopropylmalate isomerase (EC 4.2.1.33) by Neurospora crassa increased during induction in the presence of cycloheximide but was inhibited by proflavine and other inhibitors of RNA synthesis. Turnover of the enzyme once formed appeared negligible, but the message (measured as enzyme-forming capacity) had a half-life of 4 to 8 min. A comparison of the kinetics of induc...
متن کاملThe Effects of Consensus Mutations on Yeast Enzyme Triosephosphate Isomerase
Most natural proteins are only marginally stable, yet many therapeutic and industrial applications require stabilized variants. It has been shown that mutations to the most common residue in a multiple sequence alignment of protein families results in stabilization about half the time. The degree of conservation of these residues can be determined by measuring the difference between the amino a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1976
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)33378-1