A simple two step procedure for purification of the catalytic domain of chicken tryptophan hydroxylase 1 in a form suitable for crystallization

Autor: Jane Boesen, Trine V. Vendelboe, Pernille Harris, Astrid Munch, Hans Erik Mølager Christensen, Michael Ericsson Skovbo Nielsen, Charlotte Rode Petersen
Rok vydání: 2008
Předmět:
Zdroj: Protein Expression and Purification. 57:116-126
ISSN: 1046-5928
DOI: 10.1016/j.pep.2007.10.016
Popis: Tryptophan hydroxylase (TPH) [EC 1.14.16.4] catalyzes the conversion of tryptophan to 5-hydroxytryptophan, which is the first and rate-determining step in the biosynthesis of the neurotransmitter serotonin. We have expressed the catalytic domain of chicken (Gallus gallus) TPH isoform 1 in Escherichia coli in high yield. The enzyme was highly purified using only one anion exchange and one gel filtration, with a yield of 11 mg/L culture and a specific activity of 0.60 micromol/min/mg. The K(m) values were determined to K(m, tryptophan)=7.7+/-0.7 microM, K(m, BH4)=324+/-10 microM and K(m, O2)=39+/-2 microM. Substrate inhibition by tryptophan was observed at concentrations above 15 microM. Furthermore, the purified enzyme has been crystallized without 7,8-dihydro-L-biopterin and a data set to 3A resolution has been collected.
Databáze: OpenAIRE