title: Binding of thyroid hormone by heme proteins may signal protein age.
abstract: Cellular aging is thought to include the accumulation of proteins with post-translational modifications that alter degradation rates or function or both. Protein catabolism has been regarded as a randomly occurring process, but recent observations have suggested mechanisms by which old and young cells may distinguish recently-synthesized protein molecules from "old" proteins. Hemoglobin, myoglobin and other heme proteins bind thyroid hormone progressively with time and in a poorly-dissociable manner. This cumulative acquisition of thyroid hormone is postulated to be an index of molecular aging.
mesh_terms: D004912:Erythrocytes / Q000378:metabolism; D006420:Hemeproteins / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D011485:Protein Binding; D013963:Thyroid Hormones / Q000378:metabolism*; D013997:Time Factors
chemical_list: D006420:Hemeproteins; D006454:Hemoglobins; D013963:Thyroid Hormones