The cytochrome c oxidase subunit IV (COX IV) antibody is a crucial tool in mitochondrial research, targeting a key component of Complex IV in the electron transport chain. COX IV, encoded by the nuclear genome, is a regulatory subunit essential for the assembly and enzymatic activity of cytochrome c oxidase, the terminal enzyme in oxidative phosphorylation. This subunit exists in tissue-specific isoforms (e.g., COX IV-1 and COX IV-2), with COX IV-1 being ubiquitously expressed.
COX IV antibodies are widely used as mitochondrial loading controls in Western blotting and immunofluorescence due to their stable expression across various physiological conditions, unlike some metabolic proteins. They help validate mitochondrial enrichment in subcellular fractionation experiments and assess mitochondrial content in studies involving metabolic disorders, cancer, neurodegeneration, and aging. Both monoclonal and polyclonal variants are available, optimized for techniques including immunocytochemistry, immunohistochemistry, and flow cytometry.
Quality validation typically involves verifying specificity through knockdown experiments or cross-reactivity checks with other COX subunits. Researchers prioritize antibodies demonstrating clean band patterns at ~17 kDa (human) with minimal background. Its role as a "housekeeping" protein marker makes it particularly valuable in comparative studies of mitochondrial dysfunction under experimental treatments or disease states.