title: Pentamines as substrate for human spermine oxidase.
abstract: Substrate activities of various linear polyamines to human spermine oxidase (hSMO) were investigated. The activities were evaluated by monitoring the amount of H2O2 released from sample polyamines by hSMO. H2O2 was measured by a HPLC method that analyzed fluorescent dimers derived from the oxidation of homovanillic acid in the presence of horseradish peroxidase. Six triamines were tested and were found not to be hSMO substrates. Of sixteen tetramines tested, spermine (Spm) was the most active substrate, followed by homospermine and N-butylated Spm. Pentamines showed a characteristic pattern of substrate activity. Of thirteen pentamines tested, 3343 showed higher substrate activity than Spm, and 4343 showed similar activity to Spm. The activities of the other pentamines were as follows: 3443, 4443, 4344, 3344, 4334, 4444, and 3334 (in decreasing order). Product amines released from these pentamines by hSMO were then analyzed by HPLC. Triamine was the only observed product, and the amount of triamine was nearly equivalent to that of released H2O2. A marked difference in the pH dependency curves between tetramines and pentamines suggested that hSMO favored reactions with a non-protonated secondary nitrogen at the cleavage site. The Km and Vmax values for Spm and 3343 at pH 7.0 and 9.0 were consistent with the higher substrate activity of 3343 compared to Spm, as well as with the concept of a non-protonated secondary nitrogen at the cleavage site being preferred, and 3343 was well degraded at a physiological pH by hSMO.
authors: Laboratory of Bioorganic Chemistry, Department of Pharmaceutical Technochemistry, Josai University, 1–1 Keyaki-dai, Sakado, Saitama 350–0295, Japan. ktakao@josai.ac.jp
authors: Koichi
authors: K
authors: Takao
authors: Akira
authors: A
authors: Shirahata
authors: Keijiro
authors: K
authors: Samejima
authors: Robert Anthony
authors: RA
authors: Casero
authors: Kazuei
authors: K
authors: Igarashi
authors: Yoshiaki
authors: Y
authors: Sugita
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D013379:Substrate Specificity; D000097667:Polyamine Oxidase
chemical_list: D000587:Oxidoreductases Acting on CH-NH Group Donors; D000644:Quaternary Ammonium Compounds; D000097667:Polyamine Oxidase; C040648:pentamine