Novel characteristics of Selenomonas ruminantium lysine decarboxylase capable of decarboxylating both L-lysine and L-ornithine

• Published in: Bioscience, biotechnology, and biochemistry Vol. 63; no. 6; pp. 1063 - 1069
• Main Authors: Takatsuka, Y. (Tohoku Univ., Sendai (Japan)), Onoda, M, Sugiyama, T, Muramoto, K, Tomita, T, Kamio, Y
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.06.1999; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Amino Acid Sequence; Bacterial Proteins - metabolism; Bacteriology; Biological and medical sciences; CADAVERINA; CADAVERINE; Carboxy-Lyases - antagonists & inhibitors; Carboxy-Lyases - chemistry; Carboxy-Lyases - metabolism; DL-α-difluoromethyllysine; DL-α-difluoromethylornithine; Eflornithine - antagonists & inhibitors; Enzyme Inhibitors - pharmacology; Fundamental and applied biological sciences. Psychology; Kinetics; LIASAS; LISINA; LYASE; LYASES; LYSINE; Lysine - analogs & derivatives; Lysine - antagonists & inhibitors; Lysine - metabolism; lysine decarboxylase; Metabolism. Enzymes; Microbiology; Molecular Sequence Data; ORNITHINE; Ornithine - metabolism; ornithine decarboxylase; ORNITINA; SELENOMONAS; Selenomonas - enzymology; Selenomonas ruminantium; Substrate Specificity; Purification; Enzyme; Enzyme inhibitor; Lysine decarboxylase; Lyases; Bacteroidaceae; Characterization; Carbon-carbon lyases; Enzymatic activity; Carboxy-lyases; Substrate specificity; Bacteria; Selenomonas ruminantium; Kinetic parameter; Physicochemical properties
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.63.1063

Lysine decarboxylase (LDC; EC 4.1.1.18) of Selenomonas ruminantium is a constitutive enzyme and is involved in the synthesis of cadaverine, which is an essential constituent of the peptidoglycan for normal cell growth. We purified the S. ruminantium LDC by an improved method including hydrophobic chromatography and studied the fine characteristics of the enzyme. Kinetic study of LDC showed that S. ruminanitum LDC decarboxylated both L-lysine and L-ornithine with similar K m and the decarboxylase activities towards both substrates were competitively and irreversibly inhibited by DL-α-difluoromethylornithine, which is a specific inhibitor of ornithine decarboxylase (EC 4.1.1.17). We also showed a drastic descent of LDC activity owing to the degradation of LDC at entry into the stationary phase of cell growth.