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Enzyme Research
Volume 2013 (2013), Article ID 670702, 6 pages
http://dx.doi.org/10.1155/2013/670702
Research Article

Purification and Characterization of Phenylalanine Ammonia Lyase from Trichosporon cutaneum

1Food, Nutrition, and Health, University of British Columbia, 2205 East Mall, Vancouver, BC, Canada V6T 1Z4
2Department of Chemistry, University of the West Indies, Kingston, Jamaica

Received 25 June 2013; Accepted 13 August 2013

Academic Editor: Qi-Zhuang Ye

Copyright © 2013 Andrea Goldson-Barnaby and Christine H. Scaman. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Trichosporon cutaneum phenylalanine ammonia lyase was selected as a model to investigate the dual substrate activity of this family of enzymes. Sequencing of the PAL gene identified an extensive intron region at the N-terminus. Five amino acid residues differing from a prior report were identified. Highest Phe : Tyr activities ( : μmol/h g wet weight) were induced by Tyr. The enzyme has a temperature optimum of 32°C and a pH optimum of 8–8.5 and shows no metal cofactor dependence. Michaelis-Menten kinetics (Phe,  mM) and positive allostery (Tyr,  mM, Hill coefficient ) were observed. Anion exchange chromatography gave a purification fold of 50 with 20% yield. The His-Gln motif (substrate selectivity switch region) indicates the enzyme’s ability to act on both substrates.