3-hydroxyisobutyrate dehydrogenase, mitochondrial

3-Hydroxyisobutyrate dehydrogenase, mitochondrial (HIBADH) is a metabolic enzyme that catalyzes the oxidation of 3-hydroxyisobutyrate, a valine catabolism intermediate, in the mitochondrial matrix (UniProt: P31937). The protein functions in amino acid degradation and energy metabolism, reflecting its localization within mitochondria. No broad disease associations are documented in the UniProt record for this enzyme.

HIBADH shows increased abundance in Alzheimer's disease post-mortem brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein was upregulated with a mean log2 fold-change of +0.251 across one subcellular fraction in a TMT-labeled quantitative proteomics study examining four fractions (P2, P3, S2, S3) from human AD brain samples. This modest elevation may reflect altered mitochondrial bioenergetics or amino acid metabolism in the disease state, though the functional significance of this change requires further investigation.