Extended substrate specificity of serum amine oxidase: possible involvement in protein posttranslational modification.
The capacity of bovine serum amineoxidase (SAO) to oxidize free amino groups of nonconventional substrates, such as polylysine (up to 50 kDa) and some proteins as lysozyme and ribonuclease A, is described. The oxidation was quantified from the amount of H2O2 and NH3 enzymatically produced by SAO. Kinetic analysis indicated a stereospecific preference for L-configuration. Maximal oxidation rate was obtained with poly-L-lysine (9.6 kDa). After 10 h of incubation at 37 degrees C, the poly-L-lysine was partially oxidized generating 1.5 moles of H2O2 by one mole of polylysine. Denatured SAO presented very low oxidation rates with the mentioned substrates.
Wang
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X
Department of Biochemical Sciences A. Rossi Fanelli, Rome University La Sapienza, Italy.
Pietrangeli
P
P
Mateescu
M A
MA
Mondovi
B
B
D006631:Amine Oxidase (Copper-Containing); D000818:Animals; D001798:Blood Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D002417:Cattle; D006861:Hydrogen Peroxide / Q000032:analysis; D007700:Kinetics; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000096:biosynthesis / Q000097:blood* / Q000302:isolation & purification; D011107:Polylysine / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D011489:Protein Denaturation; D011499:Protein Processing, Post-Translational; D012260:Ribonucleases / Q000737:chemistry / Q000378:metabolism; D013237:Stereoisomerism; D013379:Substrate Specificity
D001798:Blood Proteins; D011107:Polylysine; D006861:Hydrogen Peroxide; D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors; D012260:Ribonucleases; D009113:Muramidase