Identification, characterization, and crystal structure of an aldo-keto reductase (AKR2E4) from the silkworm Bombyx mori

Kohji Yamamoto, David K. Wilson

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

A new member of the aldo-keto reductase (AKR) superfamily with 3-dehydroecdysone reductase activity was found in the silkworm Bombyx mori upon induction by the insecticide diazinon. The amino acid sequence showed that this enzyme belongs to the AKR2 family, and the protein was assigned the systematic name AKR2E4. In this study, recombinant AKR2E4 was expressed, purified to near homogeneity, and kinetically characterized. Additionally, its ternary structure in complex with NADP+ and citrate was refined at 1.3 Å resolution to elucidate substrate binding and catalysis. The enzyme is a 33-kDa monomer and reduces dicarbonyl compounds such as isatin and 17α-hydroxy progesterone using NADPH as a cosubstrate. No NADH-dependent activity was detected. Robust activity toward the substrate inhibitor 3-dehydroecdysone was observed, which suggests that this enzyme plays a role in regulation of the important molting hormone ecdysone. This structure constitutes the first insect AKR structure determined. Bound NADPH is located at the center of the TIM- or (β/α)8-barrel, and residues involved in catalysis are conserved.

Original languageEnglish (US)
Pages (from-to)156-163
Number of pages8
JournalArchives of Biochemistry and Biophysics
Volume538
Issue number2
DOIs
StatePublished - 2013

Keywords

  • Crystal structure
  • Enzyme specificity
  • Lepidoptera
  • NADH
  • NADPH

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Fingerprint Dive into the research topics of 'Identification, characterization, and crystal structure of an aldo-keto reductase (AKR2E4) from the silkworm Bombyx mori'. Together they form a unique fingerprint.

  • Cite this