Hydrogen peroxide induced oxidation of peroxisomal malate synthase and catalase.
Peroxisomes contain oxidases that produce H(2)O(2), which can result in protein oxidation. To test the vulnerability of peroxisomal proteins to oxidation in vivo the organelles were isolated from castor bean endosperm incubated with H(2)O(2). When peroxisomes were exposed to H(2)O(2)in vivo, the peroxisomal proteins exhibited an increase in carbonylation as detected in avidin blots of biotin hydrazide derivatized samples. Biotin-tagged peptides from trypsin digests of the proteins were analyzed by mass spectroscopy and compared to the masses of peptides from the same protein that had not been biotin-tagged and from proteins not exposed to excess H(2)O(2). H(2)O(2) exposure was found to increase the activity of catalase (CAT), and to increase the number of oxidized peptides found in CAT and malate synthase (MS). CAT had 10 peptides that were affected by in vivo exposure to H(2)O(2) and MS had 8. These sites of oxidation have definable locations within the proteins' structures.
Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA.
Pria
P
Anand
Yoon
Y
Kwak
Rahul
R
Simha
Robert P
RP
Donaldson
D000595:Amino Acid Sequence; D001360:Avidin / Q000378:metabolism; D001710:Biotin / Q000378:metabolism; D002367:Ricinus communis / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D002374:Catalase / Q000737:chemistry / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology*; D008292:Malate Synthase / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction / Q000187:drug effects; D010446:Peptide Fragments / Q000032:analysis / Q000378:metabolism; D020675:Peroxisomes / Q000201:enzymology*; D020836:Protein Structure, Quaternary; D014357:Trypsin / Q000378:metabolism
D010446:Peptide Fragments; D001360:Avidin; D001710:Biotin; D006861:Hydrogen Peroxide; D002374:Catalase; D008292:Malate Synthase; D014357:Trypsin