Effects of dopamine on N-terminus-deleted human tyrosine hydroxylase type 1 expressed in Escherichia coli.
N-Terminus-deleted mutants and wild-type human tyrosine hydroxylase type 1 were expressed in Escherichia coli (E. coli) and utilized to investigate the dopamine-induced decrease in the enzyme catalytic activity and also to identify the specific portion in the N-terminus that affects the efficiency of the inhibitory action of dopamine. Supernatants of bacterial lysates were used as enzyme samples. The pH profiles of the enzyme catalytic activity were affected according to the degree of the deletion. The deletion up to 39 amino acid residues was enough to abolish the inhibitory effect of dopamine in the basic pH range. These results suggest that the inhibition by dopamine of tyrosine hydroxylase activity is closely related to the amino acid sequence in the N-terminus of the enzyme.
Ota
A
A
Department of Physiology, Institute for Comprehensive Medical Science, School of Medicine, Fujita Health University, Aichi, Japan.
Nakashima
A
A
Mori
K
K
Nagatsu
T
T
D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004298:Dopamine / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016296:Mutagenesis; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics
D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine