Purification and Biochemical Characterization of Native and Pegylated Form of L-Asparaginase from <i>Aspergillus terreus</i> and Evaluation of Its Antiproliferative Activity

Abstract

L-asparaginase is a chemotherapeutic drug used in the treatment of lymphoblastic leukemia. In the present study, the extracellular L-asparaginase produced by strain (PC-1.7.A) of Aspergillus terreus was purified, characterized, and modified with polyethylene glycol. Moreover, its antiproliferative activity was evaluated. The apparent molecular weight of the enzyme was found to be 136 kDa. The optimal pH and temperature for the enzyme were 9.0˚C and 40˚C, respectively. The enzyme retained 100% of the activity at 40˚C for 120 min. Pegylated L-asparaginase was more thermostable and more resistant to trypsin than native enzyme. Native L-asparaginase against human normal cells did not show cytotoxicity. However, in the leukemia cell lines RS4;11 and HL60 the antiproliferative effects of native L-asparaginase were observed after 96 and 72 h of incubation, respectively. For the first time, an L-asparaginase from fungus was evaluated as an antitumor agent in human cells lines and further investigations should be conducted to improve the knowledge about this enzyme.

Development of L-Asparaginase Biobetters: Current Research Status and Review of the Desirable Quality Profiles

“…The E. coli (EcA II) and E. chrysanthemi (ErA) ASNases hydrolyzes L-glutamine up to 9% of total hydrolysis activity (high preference for L-Asn over L-Gln). Therefore, innumerable approaches to obtain ASNase with lower glutaminase activity have been investigated, such as bioprospecting other microbial sources or the modification of commercial ASNases by site-directed mutagenesis (Loureiro et al, 2012; Ardalan et al, 2018). Amino acids essential for biocatalysis in most cases were not altered since they are obligatory for effective ASNase binding to asparagine.…”

Isolation and screening of l-asparaginase free of glutaminase and urease from fungal sp.

“…Similar effect was observed when l -asparaginase from deuteromycetes Fusarium tricinctum was purified which regressed lymphosarcoma in mice (Scheetz et al 1971). Later purified extracellular l -asparaginase from A. terreus was conjugated with polyethylene glycol and it did not indicate any glutaminase activity (Loureiro 2012). Sarquis et al examined Aspergillus tamari and A. terreus for l -asparaginase production and found that asparaginase activity is reduced in the presence of urea and glutamine (Sarquis et al 2004).…”

Immunogenicity assessment of fungal l-asparaginases: an in silico approach

“…In this regard, fungal sources have been explored for their eukaryotic nature, as their similarity to humans at cellular level could reduce the unwanted immunological reactions [36,37]. Several reports [38][39][40][41] and comprehensive reviews [20, [42][43][44] have been published, revealing the potential of fungi as a feasible source of ASNase and presenting antitumor activity [45,46]. In addition to being eukaryotes, they can produce ASNase with reduced glutaminase activity [47,48].…”