title: Species-specific effects on non-enzymatic metmyoglobin reduction in vitro.
abstract: Our objectives were to determine the non-enzymatic metmyoglobin reduction properties of bovine, porcine, and equine myoglobins and to characterize the effects of pre-incubation of 4-hydroxy-2-nonenal (HNE) with myoglobins on non-enzymatic metmyoglobin reduction in vitro. Purified bovine, porcine, and equine metmyoglobins (0.05 mM) were reduced at pH 5.6 and 7.4 in the presence or absence of HNE. Rates of metmyoglobin reduction were monitored by spectrophotometry, and myoglobin adducts were characterized by high-resolution mass-spectrometry. Results showed that the species origins of individual myoglobins determined rates of non-enzymatic reduction (beef>equine>pork; P<0.05). Irrespective of species, pre-incubation of HNE myoglobin decreased non-enzymatic metmyoglobin reduction compared with control at both pH 5.6 and 7.4 (P<0.05). Mass spectrometric analysis revealed adducts of HNE with bovine, porcine, and equine myoglobins. The results indicate that the amino acid composition and the covalent binding of HNE with myoglobin can significantly decrease the ability of heme to accept electrons.
authors.affiliation: Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: N N
authors.initials: NN
authors.lastname: Elroy
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: J
authors.initials: J
authors.lastname: Rogers
authors.affiliation: Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: G G
authors.initials: GG
authors.lastname: Mafi
authors.affiliation: Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: VanOverbeke
authors.affiliation: Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: S D
authors.initials: SD
authors.lastname: Hartson
authors.affiliation: Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA. Electronic address: ranjith.ramanathan@okstate.edu.
authors.forename: R
authors.initials: R
authors.lastname: Ramanathan
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004044:Dietary Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects; D006736:Horses; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015227:Lipid Peroxidation; D008786:Metmyoglobin / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010860:Pigments, Biological / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013045:Species Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D034421:Sus scrofa
chemical_list: D000447:Aldehydes; D003432:Cross-Linking Reagents; D004044:Dietary Proteins; D010860:Pigments, Biological; D008786:Metmyoglobin; C027576:4-hydroxy-2-nonenal
keywords: Lipid oxidation; Mass spectrometry; Meat color; Metmyoglobin reduction; Myoglobin