Characterization of Recombinant Human Aromatic l‐Amino Acid Decarboxylase Expressed in COS Cells

Chiho Sumi, Hiroshi Ichinose, Toshiharu Nagatsu

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Abstract: The expression vector containing the full‐length cDNA of human aromatic l‐Amino acid decarboxylase (EC was transfected in COS cells by a modified calcium phosphate coprecip‐itation method. The cells transfected with plasmids that had a true direction of the cDNA gave a major immunoreactive band at 50 kDa. This expressed enzyme catalyzed the decarboxylation of l‐3,4‐dihydroxyphenylalanine (l‐DOPA). l‐5‐hydroxytryptophan (l‐5‐HTP) and l‐threo‐3,4‐dihydroxyphenylserine. The optimal pH of the enzyme activity with l‐DOPA as a substrate was 6.5, whereas the enzyme had a broad pH optimum when l‐5‐HTP was used as a substrate. Addition of pyridoxal phosphate to the incubation mixture greatly enhanced the activity for both l‐DOPA and l‐5‐HTP.

Original languageEnglish
Pages (from-to)1075-1078
Number of pages4
JournalJournal of neurochemistry
Issue number3
Publication statusPublished - 09-1990


All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Cellular and Molecular Neuroscience

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