Biosynthesis and characterization of a novel  L-asparaginase as a diverse biological activities agent

Abo-Stait, Hanan M.; Easa, Saadia M.; Abu Zahra, Fatma A.; Hassan, Amira A.; Ismail, Abdel-Mohsen S.

doi:10.4103/epj.epj_3_21

Biosynthesis and characterization of a novel L-asparaginase as a diverse biological activities agent

Authors

Abstract

Background and objectives
L-asparaginase (L-ASP) is a therapeutic enzyme used in the treatment of certain human cancers, especially acute lymphoblastic leukemia, as a chemotherapeutic agent. Other than as an anticancer agent, it has many applications, including in the treatment of autoimmune disorders, infectious diseases, and antibacterial activity. Microorganisms such as bacteria, fungi, and actinomycetes are very effective producers and a better source of L-ASP because they can be easily cultivated, and it is also easy to extract and purify L-ASP. The aim of this study is to formulate the production medium and to pinpoint the proper growth conditions for the chosen microorganism producing highly active L-ASP enzyme. The general properties of the crude L-ASP enzyme preparation were also determined to define the proper conditions for enzyme action. Under the specified conditions, the opportunity of the crude L-ASP enzyme for antimicrobial and antioxidant activities was determined.
Materials and methods
Eight recommended microbial isolates were screened for biologically active L-ASP enzyme productivity. Optimization of the cultural conditions for extracellular L-ASP production and also the important properties of the crude L-ASP were duly pinpointed. Finally, biological activities of the crude enzyme were explored.
Results and conclusion
Among all the screened organisms, the fungal strain was the most potent producer of an influential L-ASP enzyme. The maximum L-ASP activity of 17.85±0.579 U/reaction was obtained from medium containing glucose 0.2% (w/v) and L-asparagine 1% (w/v) at 30°C and pH 6.2. The important properties of the crude L-ASP were duly pinpointed as follows: optimum enzyme and substrate concentrations were 1 mg/ml and 1% (w/v), respectively, and optimum reaction pH and temperature were 10.7 and 45°C, respectively. Under the specified conditions, at varying concentrations, the enzyme preparation exhibited considerable 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity accompanied with nonantimicrobial activity, and this pointed out the necessity of partial purification of the crude fungal enzyme for further studies.

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