TY - JOUR
T1 - Effect of polar side chains at position 172 on thermal stability of 3- isopropylmalate dehydrogenase from Thermus thermophilus
AU - Akanuma, Satoshi
AU - Qu, Chunxu
AU - Yamagishi, Akihiko
AU - Tanaka, Nobuo
AU - Oshima, Tairo
PY - 1997/6/30
Y1 - 1997/6/30
N2 - To understand the role of the amino acid residue at position 172 in the conformational stability, four mutant enzymes of Thermus thermophilus 3- isopropylmalate dehydrogenase in which Ala172 was replaced with Asp, Glu, Asn, and Gln were prepared by site-directed mutagenesis. Three mutants were more stable than the wild-type enzyme. No significant change in catalytic properties was found in the mutant enzymes. The molecular modeling studies suggested that the enhanced thermostability of the mutant enzymes resulted from the formation of extra electrostatic interactions and/or improvement of hydrophobic packing of the interior core.
AB - To understand the role of the amino acid residue at position 172 in the conformational stability, four mutant enzymes of Thermus thermophilus 3- isopropylmalate dehydrogenase in which Ala172 was replaced with Asp, Glu, Asn, and Gln were prepared by site-directed mutagenesis. Three mutants were more stable than the wild-type enzyme. No significant change in catalytic properties was found in the mutant enzymes. The molecular modeling studies suggested that the enhanced thermostability of the mutant enzymes resulted from the formation of extra electrostatic interactions and/or improvement of hydrophobic packing of the interior core.
KW - 3-Isopropylmalate dehydrogenase
KW - Electrostatic interaction
KW - Hydrophobic packing
KW - Site-directed mutagenesis
KW - Thermal stability
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U2 - 10.1016/S0014-5793(97)00540-1
DO - 10.1016/S0014-5793(97)00540-1
M3 - Article
C2 - 9237617
AN - SCOPUS:0030785695
VL - 410
SP - 141
EP - 144
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 2-3
ER -