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Inhibition, crystal structures, and in-solution oligomeric structure of aldehyde dehydrogenase 9A1.

ABSTRACT: Aldehyde dehydrogenase 9A1 (ALDH9A1) is a human enzyme that catalyzes the NAD⁺-dependent oxidation of the carnitine precursor 4-trimethylaminobutyraldehyde to 4-N-trimethylaminobutyrate. Here we show that the broad-spectrum ALDH inhibitor diethylaminobenzaldehyde (DEAB) reversibly inhibits ALDH9A1 in a time-dependent manner. Possible mechanisms of inhibition include covalent reversible inactivation involving the thiohemiacetal intermediate and slow, tight-binding inhibition. Two crystal structures of ALDH9A1 are reported, including the first of the enzyme complexed with NAD⁺. One of the structures reveals the active conformation of the enzyme, in which the Rossmann dinucleotide-binding domain is fully ordered and the inter-domain linker adopts the canonical β-hairpin observed in other ALDH structures. The oligomeric structure of ALDH9A1 was investigated using analytical ultracentrifugation, small-angle X-ray scattering, and negative stain electron microscopy. These data show that ALDH9A1 forms the classic ALDH superfamily dimer-of-dimers tetramer in solution. Our results suggest that the presence of an aldehyde substrate and NAD⁺ promotes isomerization of the enzyme into the active conformation.

SUBMITTER: Wyatt JW

PROVIDER: S-EPMC7484307 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Inhibition, crystal structures, and in-solution oligomeric structure of aldehyde dehydrogenase 9A1.

Wyatt Jesse W JW Korasick David A DA Qureshi Insaf A IA Campbell Ashley C AC Gates Kent S KS Tanner John J JJ

Archives of biochemistry and biophysics 20200724

Aldehyde dehydrogenase 9A1 (ALDH9A1) is a human enzyme that catalyzes the NAD<sup>+</sup>-dependent oxidation of the carnitine precursor 4-trimethylaminobutyraldehyde to 4-N-trimethylaminobutyrate. Here we show that the broad-spectrum ALDH inhibitor diethylaminobenzaldehyde (DEAB) reversibly inhibits ALDH9A1 in a time-dependent manner. Possible mechanisms of inhibition include covalent reversible inactivation involving the thiohemiacetal intermediate and slow, tight-binding inhibition. Two cryst ...[more]

PMID: 32717224

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Dataset Information

Inhibition, crystal structures, and in-solution oligomeric structure of aldehyde dehydrogenase 9A1.

Publications

Inhibition, crystal structures, and in-solution oligomeric structure of aldehyde dehydrogenase 9A1.

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