title: The covalent modification of spectrin in red cell membranes by the lipid peroxidation product 4-hydroxy-2-nonenal.
abstract: Spectrin strengthens the red cell membrane through its direct association with membrane lipids and through protein-protein interactions. Spectrin loss reduces the membrane stability and results in various types of hereditary spherocytosis. However, less is known about acquired spectrin damage. Here, we showed that alpha- and beta-spectrin in human red cells are the primary targets of the lipid peroxidation product 4-hydroxy-2-nonenal (HNE) by immunoblotting and mass spectrometry analyses. The level of HNE adducts in spectrin (particularly alpha-spectrin) and several other membrane proteins was increased following the HNE treatment of red cell membrane ghosts prepared in the absence of MgATP. In contrast, ghost preparation in the presence of MgATP reduced HNE adduct formation, with preferential beta-spectrin modification and increased cross-linking of the HNE-modified spectrins. Exposure of intact red cells to HNE resulted in selective HNE-spectrin adduct formation with a similar preponderance of HNE-beta-spectrin modifications. These findings indicate that HNE adduction occurs preferentially in spectrin at the interface between the skeletal proteins and lipid bilayer in red cells and suggest that HNE-spectrin adduct aggregation results in the extrusion of damaged spectrin and membrane lipids under physiological and disease conditions.
authors.affiliation: Laboratory of Molecular Medicine, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Nobuto
authors.initials: N
authors.lastname: Arashiki
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Otsuka
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ito
authors.forename: Mira
authors.initials: M
authors.lastname: Yang
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Komatsu
authors.forename: Kota
authors.initials: K
authors.lastname: Sato
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Inaba
mesh_terms: D000447:Aldehydes / Q000378:metabolism* / Q000494:pharmacology; D000595:Amino Acid Sequence / Q000187:drug effects; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D015227:Lipid Peroxidation; D008969:Molecular Sequence Data; D013049:Spectrin / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000447:Aldehydes; D013049:Spectrin; C027576:4-hydroxy-2-nonenal