Phenylalanine 4-monooxygenase: the 'sulfoxidation polymorphism'
| Autor: | Stephen C. Mitchell, Glyn B. Steventon |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Phenylalanine hydroxylase
Phenylalanine Health Toxicology and Mutagenesis Physiology Urine Disease Biology Toxicology 030226 pharmacology & pharmacy Biochemistry 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Aromatic amino acids Humans Tyrosine Pharmacology chemistry.chemical_classification Polymorphism Genetic Carbocysteine Phenylalanine Hydroxylase General Medicine Phenotype Enzyme chemistry 030220 oncology & carcinogenesis biology.protein |
| Zdroj: | Xenobiotica. 50:51-63 |
| ISSN: | 1366-5928 0049-8254 |
| DOI: | 10.1080/00498254.2019.1636419 |
| Popis: | 1. Consistent differences in the proportion of an orally administered dose of S-carboxymethyl-l-cysteine subsequently excreted in the urine as S-oxide metabolites were reported 40 years ago. This observation suggested the existence of inter-individual variation in the ability to undertake the enzymatic S-oxygenation of this compound. Pedigree studies and investigations employing twin pairs indicated a genetically controlled phenomenon overlaid with environmental influences. It was reproducible and not related to gender or age.2. Studies undertaken in several healthy volunteer cohorts always provided similar results that were not significantly different when statistically analysed. However, when compared to these healthy populations, a preponderance of subjects exhibiting the characteristic of poor sulfoxidation of S-carboxymethyl-l-cysteine was found within groups of patients suffering from various disease conditions. The most striking of these associations were witnessed amongst subjects diagnosed with neurodegenerative disorders; although, underlying mechanisms were unknown.3. Exhaustive investigation has identified the enzyme responsible for this S-oxygenation reaction as the tetrahydrobiopterin-dependent aromatic amino acid hydroxylase, phenylalanine 4-monooxygenase classically assigned the sole function of converting phenylalanine to tyrosine. The underlying principle is discussed that enzymes traditionally associated solely with intermediary metabolism may have as yet unrecognised alternative roles in protecting the organism from potential toxic assault. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|