|NUKLEONIKA 2012, 57(3):383-387
ENZYMATIC REDUCTIVE AMINATION OF p-HYDROXY- AND PHENYLPYRUVIC ACIDS AS A METHOD OF SYNTHESIS OF L-TYROSINE AND L-PHENYLALANINE LABELLED WITH DEUTERIUM AND TRITIUM
Katarzyna Pałka1, Marianna Kańska1,2
1 Department of Chemistry, University of Warsaw, 1 L. Pasteur Str., 02-093 Warsaw, Poland
2 2nd Faculty of Medicine, Department of Biochemistry, Medical University of Warsaw,
101 Żwirki and Wigury Ave., 02-089 Warsaw, Poland
We report the synthesis of isotopomers of l-phenylalanine and l-tyrosine selectively labelled with hydrogen isotopes in the 2-position of the side chain. The deuterium or tritium label was introduced using reductive amination activity of enzyme L-phenylalanine dehydrogenase (EC 220.127.116.11). This way p-phenylpyruvic acid was converted into [2-2H]-, [2-3H]-, and doubly labelled [2-2H/3H]-isotopomers of L-phenylalanine, using deuteriated, tritiated, and mixed (DTO) incubation media, respectively. Similarly, p-hydroxyphenylpyruvic acid was converted into [2-2H]-, [2-3H]-, and [2-2H/3H]-L-tyrosine. Deuterium labelled isotopomers of L-phenylalanine and L-tyrosine can be used as markers in the investigation of abnormal metabolism of these amino acids observed in patients with inborn genetic diseases such as phenylketonuria and tyrosinemia.