A Lysozyme with Antifungal Activity from Pithecellobium dulce Seeds

Abstract

A protein of an apparent molecular mass of 14.4 kDa with antifungal activity was isolated from the seeds of Pithecellobium dulce using extraction with 100 mM Tris-HCl buffer (pH=8.0), precipitation with 80 % ammonium sulfate, and bioassay purification via Resource Q anion exchange chromatography and Superdex 200 gel filtration chromatography. The purified protein was putatively identified by tandem mass spectrometry with Mascot database searching, with the partial amino acid sequences showing a high degree of similarity to chicken egg white lysozyme. This putative plant lysozyme expressed antifungal activity with a rather high thermal stability of up to 80 °C for 15 min (at pH=8.0). It exerted an antifungal action towards Macrophomina phaseolina but displayed no antifungal activity against two other isolates, Phymatotrichopsis omnivora and Fusarium avenaceum