Biomaterial Database

Myoglobin-catalyzed hydrogen peroxide dependent arachidonic acid peroxidation. 1985

M B Grisham

Hemeproteins promote lipid hydroperoxide-dependent lipid peroxidation in vitro. Only recently have studies demonstrated that certain hemeproteins peroxidize lipids in a lipid-hydroperoxide-independent manner. To understand fully the interaction between reactive oxygen metabolites, myoglobin and lipid, we investigate the possibility that myoglobin may use xanthine oxidase-generated superoxide and/or hydrogen peroxide to catalyze peroxidation of a polyunsaturated fatty acid. Our studies demonstrate that myoglobin, in the presence of hypoxanthine and xanthine oxidase, catalyze the peroxidation of arachidonic acid. Oxy (ferrous) myoglobin appears to be the most effective catalyst for arachidonic acid peroxidation when compared to metmyglobin, hemoglobin, or ADP-iron chelates. Inhibition studies reveal that myoglobin uses hydrogen peroxide, not superoxide to form either an oxo-heme-oxidant or caged radical that initiates arachidonate peroxidation. The reactivity of this oxidant is similar to that of ferryl iron or hydroxyl free radical. Our results suggest that this reaction may be important in myocardial reperfusion injury since reoxygenation of ischemic myocardium results in a burst of xanthine oxidase-generated superoxide and hydrogen peroxide in proximity to cellular myoglobin.

UI	MeSH Term	Description	Entries
D007042	Hypoxanthines	Purine bases related to hypoxanthine, an intermediate product of uric acid synthesis and a breakdown product of adenine catabolism.
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D008315	Malondialdehyde	The dialdehyde of malonic acid.	Malonaldehyde,Propanedial,Malonylaldehyde,Malonyldialdehyde,Sodium Malondialdehyde,Malondialdehyde, Sodium
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D009211	Myoglobin	A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D002374	Catalase	An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.	Catalase A,Catalase T,Manganese Catalase,Mn Catalase
D002384	Catalysis	The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.	Catalyses
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog