Enoyl-CoA delta isomerase 1, mitochondrial

ECI1 (Enoyl-CoA delta isomerase 1, mitochondrial) is a key enzyme in mitochondrial fatty acid beta-oxidation that catalyzes the isomerization of 3-cis and 3-trans double bonds to the 2-trans form in enoyl-CoA substrates (UniProt: P42126). The enzyme processes diverse fatty acyl chain lengths with preference for 3Z-enoyl-CoAs, positioning it as a central regulator of fatty acid catabolism within mitochondria.

ECI1 is a mitochondrial protein involved in lipid metabolism with no disease associations documented in UniProt. Its role in beta-oxidation suggests relevance to energy homeostasis and mitochondrial function across tissues with high metabolic demand.

In Alzheimer's disease, ECI1 shows consistent upregulation in post-mortem AD brain tissue relative to age-matched controls, with a mean log2 fold-change of +0.59 across 2 out of 4 subcellular fractions (Chaparral AD proteomics; human TMT-labeled DDA proteomics). This upregulation may reflect compensatory metabolic changes or altered energy metabolism in AD pathophysiology.