Enoyl-CoA delta isomerase 2

Enoyl-CoA delta isomerase 2 (ECI2) is an enzyme that catalyzes the isomerization of enoyl-CoA substrates, converting both 3-cis and 3-trans double bonds into the 2-trans form across a range of lipid intermediates, with preference for 3-trans substrates (UniProt: O75521). The protein functions in fatty acid metabolism and β-oxidation pathways, which are central to cellular energy homeostasis and lipid turnover.

ECI2 localizes to subcellular compartments involved in peroxisomal and mitochondrial lipid processing. No diseases are curated in UniProt for this protein, though its metabolic function places it within pathways relevant to neuroenergetics (UniProt: O75521).

ECI2 is upregulated in Alzheimer's Disease brain tissue. Analysis of post-mortem AD brain versus age-matched controls using TMT-labeled proteomics across four subcellular fractions (P2, P3, S2, S3) revealed a mean log2 fold-change of +0.53, indicating modest but consistent elevation (Chaparral AD proteomics). This upregulation may reflect compensatory or pathological shifts in lipid metabolism associated with neurodegeneration.