@article{
author = "Fira, Đorđe and Kojić, Milan and Strahinić, Ivana and Arsenijević, Slavica and Banina, Ana and Topisirović, Ljubiša",
year = "2000",
abstract = "Enterococcus faecalis BGPM3 proizvodi proteinazu sposobnu da hidrolizuje ukupan kazein kao i frakcije αs1-, β-, i k-kazeina. Ova proteinaza, takođe, hidrolizuje želatin, ali ne deluje na denaturisani goveđi serum albumin ili hemoglobin. Ustanovljeno je da se optimalna hidroliza kazeina u prisuetvu BGPM3 proteinaze postiže na pH 6.5, a njegova maksimalna hidroliza na 37°C. Prisustvo proteolitičke aktivnosti u supernatantu, koji ne sadrži žive ćelije, ukazuje da izolat E. faecalis BGPM3 proizvodi ekstracelularnu proteinazu. Sinteza ove proteinaze se odigrava tokom celokupnog ciklusa rasta bakterije, pri čemu se maksimum proizvodnje postiže u stacionarnoj fazi. Trstman BGPM3 proteinaze sa helatorima metalnih jona dovodi do potpunog gubitka proteolitičke aktivnosti. Međutim, moguće je povratiti proteolitičku aktivnost (do 75%) ako se tretiranom enzimu dodaju joni Zn2+ što ukazuje da je BGPM3 proteinaza metaloenzim. Proteolitička aktivnost ovog enzima je inhibirana jonima Cu2+, čak i u prisustvu jona Zn2+. Eksperimentalni rezultati ukazuju da je proizvodnja BGPM3 proteinaze indudibilna, tj., dolazi do povećanja njene sinteze kada bakterija raste u prisustvu smeše oligopeptida (kazitona). Tako se dobija desetostruko povećanje proteolitičke aktivnosti u bezćelijskom supernatantu kada se pripremi iz kulture koja sadrži kaziton. Određivanje molekulske mase BGPM3 proteinaze je pokazalo da je to protein od oko 29 kDa., Enterococcus faecalis BGPM3 produces a proteinase that hydrolyzes total casein as well as α s1-, β-, and k-casein fractions. This proteinase was also able to hydrolyse gelatine, but not denatured bovine serum albumin and haemoglobin. The optimal pH of casein hydrolysis was 6.5 (determined at 30°C). Maximum caseinolytic activity was obtained at 37°C. The presence of proteolytic activity in cell-free supernatant strongly indicated that E. faecalis BGPM3 produces strictly extracellular proteinase. Proteinase production occurred through the growth cycle reaching a maximum at stationary phase. Pretreatment of the BGPM3 proteinase with metal ion chelators resulted in a total loss of proteolytic activity. Restoration of activity (75%) was obtained only with Zn2+ suggesting that the BGPM3 proteinase is zinc-metalloenzyme. Cu2+ even in the presence of Zn2+ inhibited proteolytic activity. It seems that production of proteinase is induced by oligopeptides (casitone), since 10-fold higher proteolytic activity was obtained in the cell-free supernatant prepared from the cultures containing casitone. The molecular mass determination revealed that extracellular BGPM3 proteinase has a molecular mass of about 29 kDa.",
publisher = "Srpsko biološko društvo, Beograd, i dr.",
journal = "Archives of Biological Sciences",
title = "Proizvodnja inducibilne ekstracelularne proteinaze pomoću prirodnog izolata Enterococcus faecalis BGPM3, Natural isolate Enterococcus faecalis BGPM3 produces an inducible extracellular proteinase",
pages = "76-67",
number = "2",
volume = "52",
url = "https://hdl.handle.net/21.15107/rcub_intor_792"
}
