Cold lability of the mutant forms of Escherichia coli inorganic pyrophosphatase.
The variants of Escherichia coli pyrophosphatase carrying the substitutions Glu20-->Asp, His136-->Gln or His140-->Gln are inactivated, in contrast to the wild-type enzyme, at temperatures below 25 degrees C: their activity measured at 25 degrees C decreases with decreasing the temperature of the stock enzyme solution. The inactivation is completely reversible and is explained by cold-induced dissociation of these hexameric enzymes into less active trimers.
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
I S
IS
Velichko
S E
SE
Volk
Dudarenkov VYu
N N
NN
Magretova
Chernyak VYa
A
A
Goldman
B S
BS
Cooperman
R
R
Lahti
A A
AA
Baykov
I V
IV
Velichko
D001224:Aspartic Acid; D001665:Binding Sites; D003080:Cold Temperature; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D018698:Glutamic Acid; D005973:Glutamine; D006639:Histidine; D007700:Kinetics; D046911:Macromolecular Substances; D008274:Magnesium / Q000494:pharmacology; D016297:Mutagenesis, Site-Directed; D011755:Pyrophosphatases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D013329:Structure-Activity Relationship
D046911:Macromolecular Substances; D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; D006639:Histidine; D011755:Pyrophosphatases; D008274:Magnesium