Purification of polygalacturonases produced by the pear scab pathogens, Venturia nashicola and Venturia pirina

摘要: Abstract An exopolygalacturonase and three endopolygalacturonases were purified from mycelia of pear scab pathogens, Venturia pirina nashicola. The molecular weight the isolated exoPG V. was 43 kDa, endoPGs nashicola 42 kDa as estimated by SDS–polyacrylamide gel electrophoresis. pH optimum activity 5.0. TheKm Vmaxvalues 0.08 mg ml−1and 4.44 × 10−3 mmol reducing group min−1 mg protein−1. N-terminal amino acid sequence similar to that Fusarium oxysporum f. sp. melonis, sequences fromV. races 1, 2 3 other fungal with a conserved motif ASxxxTFTxAAAxxxG.