Asian Journal of Biochemistry

Year: 2006 | Volume: 1 | Issue: 4 | Page No.: 333-337
DOI: 10.3923/ajb.2006.333.337

Effect of pH on the Synthesis of L-3,4-Dihydroxyphenylalanine by Tyrosinase of Edible Mushroom

D. Norouzian, A. Akbarzadeh, L. Teimoori, M. Nejati and A. Faranghi

Abstract: The effects of pH on the activity of tyrosinase (EC 1.14.18.1) leading to the formation of l-3, 4-dihydroxyphenylalanine (l-dopa) by using l-tyrosine as a substrate in the presence of ascorbic acid were studied. The reaction obeyed Eq. (1) and (2). The values of K^E_B and PK^E_B were calculated to be -1x10^-6 and 6 and those of K^ES_B, PK^ES_B were -2x10^-6 and 6.7, respectively. Hydrogen ions inhibited tyrosinase activity competitively.