title: Long-lived 4-oxo-2-enal-derived apparent lysine michael adducts are actually the isomeric 4-ketoamides.
abstract: There has been significant recent interest in the protein reactivity and biological activity of 4-oxo-2-nonenal (ONE), the 4-keto cousin of HNE. Despite the ability of HNE to form at least metastable Michael adducts with protein Lys residues, mass spectrometric evidence for the existence of apparent ONE-Lys Michael adducts is not supported by preparative solution studies. We herein show that the m+154 adducts on Lys residues that persist upon incubating with ONE represent the isomeric 4-ketoamides. The same type of 4-ketoamide represents the apparent Michael adduct on Lys residues formed by the carboxy-terminating ONE-like 4-oxo-2-enal arising along with ONE from the oxidation of linoleic acid.
authors.affiliation: Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Zhu
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Sayre
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000577:Amides / Q000138:chemical synthesis* / Q000737:chemistry; D000818:Animals; D001894:Borohydrides / Q000737:chemistry; D002417:Cattle; D007782:Lactoglobulins / Q000737:chemistry*; D019787:Linoleic Acid / Q000737:chemistry; D008239:Lysine / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D013997:Time Factors
chemical_list: C403894:4-oxo-2-nonenal; D000447:Aldehydes; D000577:Amides; D001894:Borohydrides; D007782:Lactoglobulins; C025364:sodium borohydride; D019787:Linoleic Acid; D008239:Lysine