Thermal stability of chimeric isopropylmalate dehydrogenase genes constructed from a thermophile and a mesophile.
Chimeric isopropylmalate dehydrogenases were constructed by connecting the genes isolated from an extreme thermophile, Thermus thermophilus, and a mesophile, Bacillus subtilis. These genes were expressed in Escherichia coli. The enzymes were purified and analysed. Enzymes of T.thermophilus and B.subtilis and chimeric enzymes showed similar enzymological characteristics except for thermal stability. The stability of each enzyme was approximately proportional to the content of the amino acid sequence from the T.thermophilus enzyme. The results suggested that amino acid residues contributing the thermal stability distribute themselves, in general, evenly at least in the N-terminal half of the amino acid sequence of T.thermophilus isopropylmalate dehydrogenase.
Numata
K
K
Department of Life Science, Tokyo Institute of Technology, Yokohama, Japan.
Muro
M
M
Akutsu
N
N
Nosoh
Y
Y
Yamagishi
A
A
Oshima
T
T
D050539:3-Isopropylmalate Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D007700:Kinetics; D008345:Manganese / Q000494:pharmacology; D008969:Molecular Sequence Data; D011189:Potassium Chloride / Q000494:pharmacology; D011489:Protein Denaturation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D013816:Thermodynamics; D016963:Thermus thermophilus / Q000201:enzymology*
D011993:Recombinant Fusion Proteins; D008345:Manganese; D011189:Potassium Chloride; D000429:Alcohol Oxidoreductases; D050539:3-Isopropylmalate Dehydrogenase