title: Catalytic site-specific inhibition of the 20S proteasome by 4-hydroxynonenal.
abstract: The proteasome is responsible for most intracellular protein degradation and is essential for cell survival. Previous research has shown that the proteasome can be inhibited by a number of oxidants, including 4-hydroxynonenal (HNE). The present study demonstrates that HNE rapidly inhibits the chymotrypsin-like activity of the 20S proteasome purified from liver. Subunits containing HNE-adducts were identified following 2D gel electrophoresis, Western immunoblotting, and analysis by MALDI-TOF MS. At a time when only the chymotrypsin-like activity was inhibited, the alpha 6/C2 subunit was uniquely modified. These results provide important molecular details regarding the catalytic site-specific inhibition of proteasome by HNE.
authors.affiliation: Department of Ophthalmology, University of Minnesota, Minneapolis, MN 55455, USA. ferri013@umn.edu
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Ferrington
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Kapphahn
mesh_terms: D000447:Aldehydes / Q000378:metabolism* / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000378:metabolism* / Q000494:pharmacology; D001665:Binding Sites; D015153:Blotting, Western; D002384:Catalysis; D002918:Chymotrypsin / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000302:isolation & purification / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism* / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D046988:Proteasome Endopeptidase Complex / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000378:metabolism
chemical_list: D000447:Aldehydes; D000975:Antioxidants; D015853:Cysteine Proteinase Inhibitors; D002918:Chymotrypsin; D014357:Trypsin; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; C027576:4-hydroxy-2-nonenal