Expression of four types of human tyrosine hydroxylase in COS cells

Abstract

AbstractAlternative splicing from a single gene produces four kinds of human tyrosine hydroxylase (types 1–4) which have structural diversity only in the N-terminal region. We attempted expression of the type 1–4 enzymes in COS cells and performed kinetic analyses. All had enzymatic activities. The Km values of the four types for L-tyrosine and 6-methyl-5,6,7,8-tetrahydropteridine were similar, although their relative homospecific activities were clearly different. The type 1 enzyme displayed the highest activity