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Dynamic interactions in the l-lactate oxidase active site facilitate substrate binding at pH4.5
Naoki Furubayashi1, Koji Inaka1, Masayuki Kamo1
1MARUWA Foods and Biosciences, Inc., 170-1, Tsutsui-cho, Yamatokoriyama, Nara, 639-1123, Japan.
Biochemical and Biophysical Research Communications
|July 2, 2021
Summary
L-lactate oxidase crystal structure reveals how l-lactate binds to the enzyme's active site. This binding involves key side chains and dynamic movements essential for enzymatic activity.
Area of Science:
- Biochemistry
- Structural Biology
- Enzymology
Background:
- L-lactate oxidase is a flavoenzyme crucial for lactate metabolism.
- Understanding its substrate binding mechanism is key to enzyme function studies.
Purpose of the Study:
- To elucidate the crystal structure of l-lactate oxidase in complex with its substrate, l-lactate.
- To investigate the molecular interactions and dynamic changes upon substrate binding.
Main Methods:
- X-ray crystallography was employed to determine the enzyme-substrate complex structure.
- High-resolution (1.33 Å) structural analysis was performed.
Main Results:
- The crystal structure clearly shows l-lactate bound to the flavin-mononucleotide (FMN) and an adjacent active site.
- Interactions with specific side chains, including H265 and D174, were identified, highlighting their role in catalysis.
- Comparisons with the free enzyme revealed dynamic structural motions upon substrate binding.
Conclusions:
- The study reveals the precise mechanism of l-lactate binding to l-lactate oxidase.
- Dynamic enzyme motions are crucial for substrate binding and catalytic progression.
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