Biomaterial Database

[Phenylalanine-4-hydroxylase activity in the liver in viral hepatitis]. 1977

A M Shaposhnikova, and M M Skachkov, and G Ia Babitskiĭ

Phenylalanine-4-hydroxylase activity was studied in liver tissue, obtained by biopsy from 5 patients with viral hepatitis and from 8 persons without parthological alterations of liver. The enzymatic activity was estimated by formation of 14C-tyrosine in presence and in absence of added cofactor 2-amine-4-hydroxy-6,7-dimethyltetrahydropteridine. Without addition of the cofactor the phenylalanine hydroxylase activity was of the same order of magnitude in liver tissue of the patients and of healthy persons. In presence of the cofactor the enzyme activity in liver of the patients with the hepatitis of moderate severity constituted 44% of the activity found in the control group. The rate of phenylalanine hydroxylation was 0.19 with 10-2 min-1 in patients with hepatitis and 0.5 with 10-2 min-1--in the control group. In severe and moderate forms of viral hepatitis the impairment of phenylalanine metabolism was due to decrease in the activity of phenylalanine-4-hydroxylase in liver tissue.

UI	MeSH Term	Description	Entries
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
D010649	Phenylalanine	An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.	Endorphenyl,L-Phenylalanine,Phenylalanine, L-Isomer,L-Isomer Phenylalanine,Phenylalanine, L Isomer
D010651	Phenylalanine Hydroxylase	An enzyme of the oxidoreductase class that catalyzes the formation of L-TYROSINE, dihydrobiopterin, and water from L-PHENYLALANINE, tetrahydrobiopterin, and oxygen. Deficiency of this enzyme may cause PHENYLKETONURIAS and PHENYLKETONURIA, MATERNAL. EC 1.14.16.1.	Phenylalanine 4-Hydroxylase,Phenylalanine 4-Monooxygenase,4-Hydroxylase, Phenylalanine,4-Monooxygenase, Phenylalanine,Hydroxylase, Phenylalanine,Phenylalanine 4 Hydroxylase,Phenylalanine 4 Monooxygenase
D010667	Phenylpyruvic Acids	A group of compounds that are derivatives of phenylpyruvic acid which has the general formula C6H5CH2COCOOH, and is a metabolite of phenylalanine. (From Dorland, 28th ed)	Acids, Phenylpyruvic
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D006525	Hepatitis, Viral, Human	INFLAMMATION of the LIVER in humans due to infection by VIRUSES. There are several significant types of human viral hepatitis with infection caused by enteric-transmission (HEPATITIS A; HEPATITIS E) or blood transfusion (HEPATITIS B; HEPATITIS C; and HEPATITIS D).	Viral Hepatitis, Human,Human Viral Hepatitides,Human Viral Hepatitis,Viral Hepatitides, Human
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006900	Hydroxylation	Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)	Hydroxylations
D001706	Biopsy	Removal and pathologic examination of specimens from the living body.	Biopsies
D014443	Tyrosine	A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.	L-Tyrosine,Tyrosine, L-isomer,para-Tyrosine,L Tyrosine,Tyrosine, L isomer,para Tyrosine