Hemopexin is an acute-phase protein that plays a major protective role against oxidative stress through its heme-scavenging activities. Hemopexin binds heme with high affinity and is critical for recycling the iron bound to heme molecules and for protecting against heme-induced cellular damage. Free heme, when released or lost from proteins like hemoglobin, can catalyze the formation of reactive oxygen species. Heme is lipophilic and interchelates into lipid membranes and participate in the formation of highly-toxic hydroxyl radicals. Hemopexin may also protect against the heme-mediated oxidation of LDL cholesterol. Hemopexin may also serve an anti-inflammatory role via the negative regulation of IL-6 and TNF-α secretion by activated macrophages.
