Biomaterial Database

Kinetic properties of human liver tryptophan pyrrolase. 1991

Y Minatogawa, and I S Matsui, and R Kido

Department of Biochemistry, Wakayama Medical College, Japan.

Human liver tryptophan pyrrolase (TPO) activity exhibited substrate level regulation. TPO showed biphasic activity to tryptophan when low ascorbate was used as an activator. The high affinity form (Km for tryptophan: 0.05 mM) was promoted by low ascorbate and low tryptophan. The low affinity form (Km for tryptophan: 0.4 mM) was induced by high concentrations of tryptophan or ascorbate. Both high and low affinity forms showed the same affinity to oxygen. The high affinity form was also induced by pyrroloquinoline quinone, but this effect was decreased by catalase, suggesting the participation of H2O2.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001205	Ascorbic Acid	A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.	Vitamin C,Ascorbic Acid, Monosodium Salt,Ferrous Ascorbate,Hybrin,L-Ascorbic Acid,Magnesium Ascorbate,Magnesium Ascorbicum,Magnesium di-L-Ascorbate,Magnorbin,Sodium Ascorbate,Acid, Ascorbic,Acid, L-Ascorbic,Ascorbate, Ferrous,Ascorbate, Magnesium,Ascorbate, Sodium,L Ascorbic Acid,Magnesium di L Ascorbate,di-L-Ascorbate, Magnesium
D014364	Tryptophan	An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.	Ardeydorm,Ardeytropin,L-Tryptophan,L-Tryptophan-ratiopharm,Levotryptophan,Lyphan,Naturruhe,Optimax,PMS-Tryptophan,Trofan,Tryptacin,Tryptan,Tryptophan Metabolism Alterations,ratio-Tryptophan,L Tryptophan,L Tryptophan ratiopharm,PMS Tryptophan,ratio Tryptophan
D014366	Tryptophan Oxygenase	A dioxygenase with specificity for the oxidation of the indoleamine ring of TRYPTOPHAN. It is a LIVER-specific enzyme that is the first and rate limiting enzyme in the kynurenine pathway of TRYPTOPHAN catabolism.	Tryptophan Pyrrolase,TDO Dioxygenase,Tryptophan 2,3-Dioxygenase,2,3-Dioxygenase, Tryptophan,Dioxygenase, TDO,Oxygenase, Tryptophan,Pyrrolase, Tryptophan,Tryptophan 2,3 Dioxygenase
D015363	Quinolones	A group of derivatives of naphthyridine carboxylic acid, quinoline carboxylic acid, or NALIDIXIC ACID.	Ketoquinoline,Ketoquinolines,Oxoquinoline,Oxoquinolines,Quinolinone,Quinolinones,Quinolone
D045542	PQQ Cofactor	A pyrrolo-quinoline having two adjacent keto-groups at the 4 and 5 positions and three acidic carboxyl groups. It is a coenzyme of some DEHYDROGENASES.	Methoxatin,2,7,9-Tricarboxy-1H-Pyrrolo-(2,3-f)Quinoline-4,5-Dione,2,7,9-Tricarboxypyrroloquinoline Quinone,4,5-Dihydro-4,5-Dioxo-1-H-Pyrrolo(2,3-f)Quinoline-2,7,9-Tricarboxylic Acid,Coenzyme PQQ,PQQ Coenzyme,Pyrrolo-Quinoline Quinone,Pyrroloquinoline Quinone,Coenzyme, PQQ,Cofactor, PQQ,PQQ, Coenzyme,Pyrrolo Quinoline Quinone,Quinone, Pyrrolo-Quinoline,Quinone, Pyrroloquinoline