ABSTRACT: An increased activity in phenylalanine ammonia lyase (EC 4.3.1.24, PAL) enzyme in lucerne seedlings (Medicago sativa L. cv. Vertus) following inoculation with Verticillium dahliae was measured after 48 h of inoculation.  Purifications of PAL with 0-50% (NH4)2SO4 precipitation and Sephadex G-100 gel filtration resulted in 1.75 and 1.97 fold increases with 75 and 60 % recoveries, respectively.  This study showed that the purification of the enzyme clearly resulted in significant differences in respect to activities between fractions.  This property could be important for further characterization of pathogen-related proteins.

Özet: Verticillium dahliae ile inokule edilen yonca fidelerinden (Medicago sativa L. cv. Vertus ) elde edilen fenilalanin amonia lyaz (EC 4.3.1.24, PAL) enzim aktivitesindeki artış inokulasyondan 48 saat sonra ölçülmüştür.  PAL enziminin % 0-50 (NH4)2SO4 ve Sephadex G-100 jel filtrasyon yöntemi ile saflaştırılması, %75 ve %60 lık geri kazanım ve 1.75 ve 1.97 lik bir artışa yol açmıştır.  Enzim saflaştırması fraksiyonlar arasında aktivite açısından önemli farklılıkların ortaya çıkmasına neden olmuştur.  Bu özellik patojen ile ilgili proteinlerin detaylı karakterizasyonu için önemlidir.  Anahtar Kelimeler: Amonyum sulfat, jel filtrasyonu, Verticillium, yonca, PAL.    Stepwise Purification of Phenylalanine Ammonia Lyase (PAL) Enzyme Obtained from Lucerne (Medicago sativa cv. Vertus) Inoculated with Verticillium dahliae   Abstract: An increased activity in phenylalanine ammonia lyase (EC 4.3.1.24, PAL) enzyme in lucerne seedlings (Medicago sativa L. cv. Vertus) following inoculation with Verticillium dahliae was measured after 48 h of inoculation.  Purifications of PAL with 0-50% (NH4)2SO4 precipitation and Sephadex G-100 gel filtration resulted in 1.75 and 1.97 fold increases with 75 and 60 % recoveries, respectively.  This study showed that the purification of the enzyme clearly resulted in significant differences in respect to activities between fractions.  This property could be important for further characterization of pathogen-related proteins. Key Words: Ammonium sulphate precipitation, gel filtration, Verticillium, lucerne, PAL.