부산대학교 도서관

L-asparaginase has been widely accepted as a standard anticancer drug for acute lymphoblastic leukaemia (ALL). Presently in L-asparaginase biotherapeutic applications, the main focus is developing new L-asparaginase with minimal or without any glutaminase activity to reduce the associated adverse drug reactions. In this study, Bacillus flexus strain SS (NCBI GenBank Accession Number MN420983) was identified as a promising producer of L-asparaginase. L-asparaginase production was optimized by response surface methodology statistical bioprocess modelling, and enzyme yield of 25.08 IU/mL was reached at the bioreactor scale. The purification of L-asparaginase included ammonium sulfate precipitation, ion-exchange chromatography and size exclusion chromatography yielding 5.27-fold purification. The SDS-PAGE and CE-SDS revealed the monomeric L-asparaginase with molecular weight of 33 kDa. The purified enzyme was highly specific to substrate L-Asn and free from glutaminase activity. The anticancer activity of purified L-asparaginase was found specific against tumor cell lines SKBR3 (IC50 = 0.8 µg/mL), WIL2-S (IC50 = 16.2 µg/mL), and TF-1 (IC50 = 47 µg/mL), but not against negative control HUVEC cells. Therefore, L-asparaginase from B. flexus SS with no glutaminase activity could be a potential new candidate for anticancer drug for ALL with reduced adverse effects. [ABSTRACT FROM AUTHOR]