title: L-Serine, D- and L-proline and alanine as respiratory substrates of Helicobacter pylori: correlation between in vitro and in vivo amino acid levels.
abstract: Helicobacter pylori whole cells showed high rates of oxygen uptake with L-serine and L-proline as respiratory substrates, and somewhat lower rates with D-alanine and D-proline. These respiratory activities were inhibited by rotenone and antimycin A at low concentrations. Since pyruvate was produced from L-serine and D- and L-alanine in whole cells, the respiratory activities with these amino acids as substrates occurred via pyruvate. Whole cells showed 2,6-dichlorophenolindophenol (DCIP)-reducing activities with D- and L-proline and D-alanine as substrates, suggesting that hydrogen removed from these amino acids also participated in oxygen uptake by the whole cells. High amounts of L-proline, D- and L-alanine, and L-serine were present in H. pylori cells, and these amino acids also predominated in samples of human gastric juice. H. pylori seems to utilize D- and L-proline, D-alanine and L-serine as important energy sources in its habitat of the mucous layer of the stomach.
authors.affiliation: Department of Bacteriology, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Nagata
authors.affiliation: Department of Materials and Applied Chemistry, College of Science and Technology, Nihon University, 1-8-14 Kanda, Surugadai, Chiyoda-ku, Tokyo 101-8308, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Nagata
authors.affiliation: First Department of Medicine, Yamanashi Medical University, Kofu, Yamanashi, 409-3898, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sato
authors.affiliation: First Department of Medicine, Yamanashi Medical University, Kofu, Yamanashi, 409-3898, Japan.
authors.forename: Masayuki A
authors.initials: MA
authors.lastname: Fujino
authors.affiliation: Department of Bacteriology, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Department of Bacteriology, Hyogo College of Medicine, 1-1 Mukogawa, Nishinomiya, Hyogo 663-8501, Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Tamura
mesh_terms: D015086:2,6-Dichloroindophenol / Q000378:metabolism; D000409:Alanine / Q000737:chemistry / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism; D005750:Gastric Juice / Q000378:metabolism; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011392:Proline / Q000737:chemistry / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism; D012694:Serine / Q000737:chemistry / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D012694:Serine; D000641:Ammonia; D019289:Pyruvic Acid; D011392:Proline; D015086:2,6-Dichloroindophenol; D000409:Alanine