1.1.3.2: L-lactate oxidase
This is an abbreviated version!
For detailed information about L-lactate oxidase, go to the full flat file.
Reaction
Synonyms
AvLOX, L-lactate oxidase, LctO, LOX
ECTree
Advanced search results
Engineering
Engineering on EC 1.1.3.2 - L-lactate oxidase
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
A95G
A96L
A96L/N212K
the double mutant shows a drastic decrease compared with that of the wild type (0.16% using 20 mM L-lactate) and A96L mutant (1.9% using 20 mM L-lactate). The mutant enzyme is more stable than the wild type enzyme and the N212K single mutant. After modification by phenazine ethosulfate, the Ala96Leu/Asn212Lys double mutant shows the highest oxidation peak in the presence of L-lactate, whereas the electrodes with the phenazine ethosulfate-modified wild type or Ala96Leu mutant do not
R181K
mutation in conserved residue, efficiency of reduction of the oxidized flavin by L-lactate is greatly reduced
R181K/R268K
mutation in conserved residue, efficiency of reduction of the oxidized flavin by L-lactate is greatly reduced
R181M
mutation in conserved residue, efficiency of reduction of the oxidized flavin by L-lactate is greatly reduced
R268K
mutation in conserved residue, efficiency of reduction of the oxidized flavin by L-lactate is greatly reduced. Mutation also results in a slow conversion of the 8-CH3-substituent of FMN to yield 8-formyl-FMN
S218C
introduction of a site for chemical modification, about 50% of wild-type activity
Y191A
28fold decrease in release of pyruvate, , binding of L-lactate is strongly affected
Y191L
19fold decrease in release of pyruvate, binding of L-lactate is strongly affected
Y215F
mutation in binding pocket, mutant shows slowed flavin reduction and oxidation by up to 33-fold. Pyruvate release is also decelerated and is the slowest step overall
Y215H Y215F
mutation in binding pocket, mutant shows slowed flavin reduction and oxidation by up to 33-fold. Pyruvate release is also decelerated
A96L
-
the mutant enzyme is more stable than the wild type enzyme and the N212K single mutant
-
A96L/N212K
-
the double mutant shows a drastic decrease compared with that of the wild type (0.16% using 20 mM L-lactate) and A96L mutant (1.9% using 20 mM L-lactate). The mutant enzyme is more stable than the wild type enzyme and the N212K single mutant. After modification by phenazine ethosulfate, the Ala96Leu/Asn212Lys double mutant shows the highest oxidation peak in the presence of L-lactate, whereas the electrodes with the phenazine ethosulfate-modified wild type or Ala96Leu mutant do not
-
F212V
change in the active site to that of Arabidopsis thaliana glycolate oxidase 2, 25fold decrease in the L-lactate oxidase/glycolate oxidase activity ratio
L112W
change in the active site to that of Arabidopsis thaliana glycolate oxidase 2, 2fold decrease in the L-lactate oxidase/glycolate oxidase activity ratio
M82T
change in the active site to that of Arabidopsis thaliana glycolate oxidase 2, 10fold decrease in the L-lactate oxidase/glycolate oxidase activity ratio
M82T/L112W/F212V
change in the active site to that of Arabidopsis thaliana glycolate oxidase 2, reverse the L-lactate oxidase/glycolate oxidase activity ratio
additional information
gene variant type 2 reveals a 51-nucleotide insertion in LctO, resulting in a 17-amino-acid repeat in the gene product, and formation of an extra loop in the monomeric protein structure. Upon expression in Escherichia coli, the higher-molecular-weight type 2 enzyme exhibits higher activity. Growth rates of Streptococcus iniae expressing the type 2 enzyme are not reduced at lactate concentrations of 0.3% and 0.5%, whereas a strain expressing the type 1 enzyme exhibits reduced growth rates at these lactate concentrations
activity with L-lactate similar to wild-type, increased activity with longer chain L-alpha-hydroxyacids such as alpha-hydroxy-n-butyric acid, alpha-hydroxy-n-valeric acid, and also with L-mandelic acid. Reduction of the enzyme bound flavin by substrates is the rate-limiting step in A95G
A95G
mutant is 3fold more reactive towards 2,6-dichlorophenol-indophenol than O2, whereas wildtype is 14fold more reactive towards O2 than 2,6-dichlorophenol-indophenol. Substituted 1,4-benzoquinones are up to 5fold better electron acceptors for reaction with L-lactate-reduced A95G variant than wild-type
engineering the enzyme in order to minimize the effects of oxygen interference on sensor strips. Mutant A96L shows a drastic reduction in oxidase activity using molecular oxygen as the electron acceptor and a small increase in dehydrogenase activity employing an artificial electron acceptor. After immobilization on a screen-printed carbon electrode and under argon or atmospheric conditions, the response current increases linearly from 0.05 to 0.5 mM L-lactate for both wild-type and mutant A96L. Under atmospheric conditions, the response of wild-type electrode is suppressed by 9-12% due to oxygen interference. The mutant maintains 56-69% of the response current at the same L-lactate level and minimizes the relative bias error to -19% from -49% of wild-type
A96L
the mutant enzyme is more stable than the wild type enzyme and the N212K single mutant