The structure of the covalent adduct formed by the interaction of 3-dimethylamino-1-propyne and the flavine of mitochondrial amine oxidase.
3-Dimethylamino-1-propyne irreversibly inactivates mitochondrial monoamine oxidase from bovine liver. The inactivation results in the loss of absorption in the 450-500-nm region of the flavine spectrum and a concomitant increase in absorbance at 410 nm. For the enzyme-bound adduct epsilon410 = 28000. The spectral properties of the adduct of the liver enzyme with 3-dimethylamino-1-propyne are similar to those observed when the pig kidney enzyme is inactivated with pargyline (Chuang et al. (1974), J. Biol. Chem. 249, 2381). From a proteolytic digest of the enzyme inactivated with labeled inhibitor a flavine peptide has been isolated which contains 1 mol of inactivator/mol of flavine. The chemical and spectral properties of the adduct are those of compounds containing the structure --N--CH==CH--CH==N+ less than. It was concluded that the flavine-inhibtor adduct is a N-5 substituted dihydroflavine and its structure has been determined.
D000480:Alkynes / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004123:Dimethylamines / Q000494:pharmacology; D005415:Flavins / Q000302:isolation & purification; D006037:Glyoxal; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008930:Mitochondria, Liver / Q000201:enzymology*; D008968:Molecular Conformation; D008996:Monoamine Oxidase Inhibitors; D011485:Protein Binding; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet
D000480:Alkynes; D004123:Dimethylamines; D005415:Flavins; D008996:Monoamine Oxidase Inhibitors; D006037:Glyoxal; C011785:3-dimethylamino-1-propyne