Identification of protein-receptor components required for the import of prealdehyde dehydrogenase into rat liver mitochondria.
Mitochondrial aldehyde dehydrogenase is synthesized as a high-molecular-weight precursor in cytosol and transported into mitochondrial matrix space where it is processed to the mature enzyme. To identify components of the transport machinery on liver mitochondria, anti-idiotypic antibodies against the rabbit anti-prealdehyde dehydrogenase signal peptide antibodies were produced in chicken eggs and rabbit. Both anti-idiotypic antibodies inhibited the import of prealdehyde dehydrogenase (pALDH) into isolated rat liver mitochondria. The rabbit anti-idiotypic antibody could recognize by Western blotting five mitochondrial membrane proteins with apparent molecular weights of 66, 60, 42, 34, and 29 kDa. The anti-idiotypic antibodies were cross-linked to mitochondrial membrane proteins using sulfosuccinimidyl 2-(p-azidosalicylamido)ethyl-1,3'-dithiopropionate which is an iodinatable, heterofunctional, and photoreactive cross-linker. Mitochondrial proteins with apparent molecular weights of 66, 60, and 42 kDa were identified using the chicken antibody. The 66- and 34-kDa proteins were cross-linked to the rabbit antibody as the major components and the 42-kDa protein as a minor one. Antibodies against the 60- and 42-kDa proteins, as well as Fab fragments, inhibited the import of pALDH, suggesting that these proteins are receptor/translocator components for pALDH import.
D000444:Aldehyde Dehydrogenase / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D001692:Biological Transport; D002417:Cattle; D015151:Immunoblotting; D008297:Male; D008565:Membrane Proteins / Q000032:analysis; D008930:Mitochondria, Liver / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis*
D000888:Antibodies, Anti-Idiotypic; D008565:Membrane Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D000444:Aldehyde Dehydrogenase