A basic peroxidase from wheat kernel with antifungal activity

A basic heme-peroxidase (WP1) was purified to homogeneity from wheat (Triti cum aestivum) kernels. The protein was not glycosylated and exhibited a mol ecular mass of 36 kDa and a pl of 8.0. The N-terminal amino acid sequence r evealed a very high similarity with a wheat flour peroxidase allergen assoc iated with baker's asthma. WPI showed indole-3-acetic acid oxidase activity in the presence of Mn2+ and phenolic cofactors. Antifungal assays performe d in vitro towards phytopathogenic fungi indicated that WPI was active in i nhibiting germ tube elongation. This first report on antifungal properties of a heme-peroxidase gives experimental support to the idea that peroxidase s play a defensive role against invading pathogens. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.