title: C1q binding to mitochondria: a possible artefact?
abstract: Mitochondrial preparations, obtained from human tonsils and from rat spleen, liver, heart, and kidney tissues, bound [125I]C1q with affinities of 10(7)-10(8)M-1. The binding of C1q was not affected by treatment of the mitochondrial preparations with pronase, trypsin, or phospholipase D, but it was lowered 5-6-fold following treatment of the mitochondria with DNase and RNase. Binding of C1q to mitochondrial preparations was also greatly diminished by limited chemical modification of C1q with cyclohexane-1,2-dione. It is suggested that the reported binding of C1q to mitochondria may have arisen from the protein binding to DNA and/or RNA contaminating the mitochondrial preparations.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D003166:Complement Activating Enzymes / Q000378:metabolism*; D015922:Complement C1q; D003512:Cyclohexanones / Q000494:pharmacology; D003851:Deoxyribonucleases / Q000494:pharmacology; D006801:Humans; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D008929:Mitochondria, Heart / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism; D014066:Palatine Tonsil / Q000648:ultrastructure; D010739:Phospholipase D / Q000494:pharmacology; D011402:Pronase / Q000494:pharmacology; D051381:Rats; D012260:Ribonucleases / Q000494:pharmacology; D013154:Spleen / Q000648:ultrastructure; D014357:Trypsin / Q000494:pharmacology
chemical_list: D003512:Cyclohexanones; C018031:1,2-cyclohexanedione; D015922:Complement C1q; D003166:Complement Activating Enzymes; D003851:Deoxyribonucleases; D012260:Ribonucleases; D010739:Phospholipase D; D014357:Trypsin; D011402:Pronase