We have investigated some biochemical properties of elastase from a new strain of Pseudomonas aeruginosa (SES 938-1). Activities were measured at 410 nm using N-succinyl-L-(ala)3-p-nitroanilide as substrate. | Tr. J. of Biology 22 (1998) 181-188 © TÜBİTAK Biochemical Characterization of Elastase From Pseudomonas aeruginosa SES 938-1 Semra KOCABIYIK and Ezgi ERGİN Middle East Technical University, Department of Biological Sciences, 06531 Ankara-TURKEY Received: Abstract: We have investigated some biochemical properties of elastase from a new strain of Pseudomonas aeruginosa (SES 938-1). Activities were measured at 410 nm using N-succinyl-L-(ala) 3 p-nitroanilide as substrate. The elastase activity followed Michaelis-Menten kinetics over the substrate range of mM with the apparent K value of mM. Optimum activity was observed m at 36 °C and pH . elastase activity was inhibited by metal chelating agents and high concentrations 2+ 2+ 2+ of Mn , Zn and Ni . The results obtained suggest that elastase from P. aeruginosa SES 938-1 is a neutral metalloproteinase. Pseudomonas aeruginosa SES-938-1’den İzole Edilen Elastazın Biyokimyasal Karakterizasyonu Özet: Yeni Bir Pseudomonas aeruginosa suşundan (SES931-1-1) izole edilen elastazin bazı biyokimyasal özelliklerini araştırdık. Aktivite ölçümleri 420 nm de N-succinyl-L-(al)3-p-nitroanilide substrat olarak kullanılarak yapılmıştır. elastaz aktivitesi mM subtstrat konsantrasyonu sınırında Michealis-Menten kinetiğine uymakta olup görünür Km değeri mM olarak bulunmuştur. Optimum enzim aktivitesi 36 °C ve pH ’da gözlenmiştir. Enzim aktivitesi metal tutucu ajanlar ve yüksek konsantrasyolarda Mn+2 , Zn+2 ve Ni+2 tarafından inhibe edilmektedir. Bu sonuçlar P. aeruginosa SES938-1 elastazının bir nötral metalloproteinaz olduğunu göstermektedir. Introduction Among the various factors produced by the opportunistic human pathogen Pseudomonas aeruginosa elastase has the primary importance (1-3). Purified elastase is capable of degrading several molecules of biological significance, including elastin (4), collogens (5), immunoglobulins (6), complement components (7), serum α1-proteinase .