Malic Enzyme of Escherichia coli
نویسندگان
چکیده
The TPN+-specitk malic enzyme from Escherichia coli has been purified from malate-grown cells. An approximately loo-fold purified preparation is activated by NH4+ and K+ ions. The enzyme is inhibited by acetyl coenzyme A, oxalacetate, TPNH, and DPNH in an allosteric manner. Glycine at concentration ranges above 0.5 M has been shown to activate the enzyme as well as to desensitize it reversibly to the effect of various inhibitors, including DPNH. From teleological arguments it has been concluded that the complex activity controls of malic enzyme are necessitated in bacteria because of the absence of rigid compartmentation controls available to higher organisms.
منابع مشابه
Metabolic flux analysis for succinic acid production by recombinant Escherichia coli with amplified malic enzyme activity.
A pfl ldhA double mutant Escherichia coli strain NZN111 was used to produce succinic acid by overexpressing the E. coli malic enzyme. Escherichia coli strain NZN111 harboring pTrcML produced 6 and 8 g/L of succinic acid from 20 g/L of glucose in flask culture at 37 degrees C and 30 degrees C, respectively. When NZN111(pTrcML) was cultured at 30 degrees C with intermittent glucose feeding the fi...
متن کاملProduction of succinic acid through overexpression of NAD(+)-dependent malic enzyme in an Escherichia coli mutant.
NAD(+)-dependent malic enzyme was cloned from the Escherichia coli genome by PCR based on the published partial sequence of the gene. The enzyme was overexpressed and purified to near homogeneity in two chromatographic steps and was analyzed kinetically in the forward and reverse directions. The Km values determined in the presence of saturating cofactor and manganese ion were 0.26 mM for malat...
متن کاملNicotinamide adenine dinucleotide phosphate-malic enzyme of rat liver. Purification, properties, and immunochemical studies.
Rat liver malic enzyme (EC 1.1.1.40) was purified from livers of rats fasted and refed a high sucrose diet containing 1% desiccated thyroid powder. The purification was accomplished by a six-step procedure. The specific activity of the purified enzyme was increased 181-fold above that of the initial high speed supernatant of liver extracts. Slight additional purification of malic enzyme was ach...
متن کاملProperties of mutants of Escherichia coli lacking malic dehydrogenase and their revertants.
Mutants of Escherichia coli lacking malic dehydrogenase activity (mdh) were incapable of growth on acetate", succinate- or malate/mineral medium. Revertants of mdh strains which had regained the ability to grow on C4-dicarboxylic acids could be divided into two distinct classes. One type of revertant had regained the ability to synthesize functional malic dehydrogenase. The other type of revert...
متن کاملCloning and optimization of phytase enzyme gene expression in Escherichia coli
Introduction Phytase is an enzyme that has the ability to break down phytic acid into myoinositol and mineral phosphate, and widely uses as an additive in animal foods. The aim of this study was to achieve a high level of bacterial phytase expression in PET26b expression host. Materials and Methods To generate the recombinant phytase enzyme, the target gene was introduced into the expression ...
متن کامل