Effect of chemical and physical parameters on the production of l-asparaginase from a newly isolated Serratia marcescens SK-07

l-asparaginase production and enhancement by Sarocladium strictum: In vitro evaluation of anti-cancerous properties

AIMS

Utilization of l-asparaginase has been one of the effective strategies for the treatment of lymphoblastic leukaemia. Since the currently used bacterial l-asparaginase causes side effects, searching for new enzyme sources has been an active field of research. This study focuses on the characterization of an l-asparaginase-producing fungal strain.

METHODS AND RESULTS

Sarocladium strictum was identified as a potent enzyme-producing strain. For the enhancement of enzyme production, we used two-level factorial design and response surface methodology. The optimization of significant factors showed a 1·84-fold increase in enzyme production. The K_m and V_max values of the enzyme were 9·74 mmol l^-1 and 8·19 μmol min^-1 . The toxicity of the produced l-asparaginase was measured on K562 and HL60 cancer cell lines and L6 as normal cells. The IC₅₀ values were calculated as 0·4 and 0·5 IU ml^-1 for K562 and HL60 respectively and no significant effect was observed in L6. BrdU proliferation and caspase-3 activity assay in l-asparaginase treated HL60 and K562 cells indicated that cell proliferation rates and apoptotic cell death were reduced.

CONCLUSIONS

The cytotoxic properties of the produced fungal enzyme indicated significant growth inhibition in cancer cells while having a little toxic effect on normal cells. The possibility of mass production alongside having suitable cytotoxic and kinetic properties suggest the probable use of the produced l-asparaginase for further researches as a potential chemotherapeutic agent.

SIGNIFICANCE AND IMPACT OF THE STUDY

The lack of significant l-glutaminase activity and promising toxicity properties in S. strictum and the closer evolutionary relativeness of fungi enzymes to human enzymes compared to bacterial enzymes suggest a new source with lower toxicity and anti-cancerous properties, causing less side effect problems.

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

L-Asparaginase (ASNase) is a vital component of the first line treatment of acute lymphoblastic leukemia (ALL), an aggressive type of blood cancer expected to afflict over 53,000 people worldwide by 2020. More recently, ASNase has also been shown to have potential for preventing metastasis from solid tumors. The ASNase treatment is, however, characterized by a plethora of potential side effects, ranging from immune reactions to severe toxicity. Consequently, in accordance with Quality-by-Design (QbD) principles, ingenious new products tailored to minimize adverse reactions while increasing patient survival have been devised. In the following pages, the reader is invited for a brief discussion on the most recent developments in this field. Firstly, the review presents an outline of the recent improvements on the manufacturing and formulation processes, which can severely influence important aspects of the product quality profile, such as contamination, aggregation and enzymatic activity. Following, the most recent advances in protein engineering applied to the development of biobetter ASNases (i.e., with reduced glutaminase activity, proteolysis resistant and less immunogenic) using techniques such as site-directed mutagenesis, molecular dynamics, PEGylation, PASylation and bioconjugation are discussed. Afterwards, the attention is shifted toward nanomedicine including technologies such as encapsulation and immobilization, which aim at improving ASNase pharmacokinetics. Besides discussing the results of the most innovative and representative academic research, the review provides an overview of the products already available on the market or in the latest stages of development. With this, the review is intended to provide a solid background for the current product development and underpin the discussions on the target quality profile of future ASNase-based pharmaceuticals.

Isolation, Purification, Characterisation and Application of L-ASNase: A Review

BACKGROUND

L-ASNase (L-asparagine aminohydrolase EC 3.5.1.1) is used for the conversion of L-asparagine to L-aspartic acid and ammonia and also it was found as an agent of chemotherapeutic property according to recent patents. It is known as an anti-cancer agent and recently it has received an immense attention. Various microorganisms have the ability to secrete the L-ASNase. It is famous world-wide as anti-tumor medicine for acute lymphoblastic leukemia and lymphosarcoma. L-ASNase helps in deamination of Asparagine and Glutamine.

SOURCE

L-ASNase mainly found in two bacterial sources; Escherichia coli and Erwinia carotovora. Isolation from plants: Endophytes were also a great source of L-ASNase. It was isolated from four types of plants named as; C. citratus, O. diffusa, M. koengii, and also P. bleo.

APPLICATIONS

L-ASNase is used as a potential anti-tumor medicine. It plays a very much essential role for the growth of tumor cells. Tumor cells require a lot of asparagine for their growth. But ASNase converts to aspartate and ammonia from asparagine. So the tumor cell does not proliferate and fails to survive. The L-ASNase is used as the medicine for the major type of cancer like acute lymphocytic leukemia (ALL), brain. It also used as a medicine for central nervous system (CNS) tumors, and also for neuroblastoma. Two types of L-ASNase have been found.

CONCLUSION

L-ASNase becomes a powerful anti-tumor medicine and researchers should develop a potent strain of asparaginase which can produce asparaginase in the industrial level. It is also used in the pharmaceutical industry and food industry on a broader scale.

Screening and characterization of extracelluar L-asparaginase producing Bacillus subtilis strain hswx88, isolated from Taptapani hotspring of Odisha, India

OBJECTIVE

To screen and isolate an eco-friendly, a thermophilic and potent L-asparaginase producing bacterium, with novel immunological properties that may obviates hypersensitivity reactions.

METHODS

In the present study bacterial strain isolated for extracellular L-asparaginase production from hotspring, identified by morphological, biochemical and physiological tests followed by 16S rDNA technology and the L-asparaginase production ability was tested by both semi quantitative and quantitative enzymatic assay.

RESULTS

The bacterial strain was identified as Bacillus subtilis strain hswx88 (GenBank Accession Number: JQ237656.1). The extracellular enzyme yielding capacity isolate Bacillus subtilis strain hswx88 (23.8 IU/mL) was found to be 1.7 and 14.5 times higher than the reference organism Pectobacterium carotovorum MTCC 1428 (14.2 IU/mL) and Bacillus sp. BCCS 034 (1.64 IU/mL).

CONCLUSION

The isolate is eco-friendly and useful to produce bulk quantity of extracellular, thermophilic L-asparaginase for the treatment of various tumor cases and for preparation of acrylamide free fry food preparation.

Cloning, expression, and characterization of L-asparaginase from a newly isolated Bacillus subtilis B11-06

This study focused on the cloning, overexpression, and characterization of the gene encoding L-asparaginase (ansZ) from a nonpathogenic strain of Bacillus subtilis B11-06. The recombinant enzyme showed high thermostability and low affinity to L-glutamine. The ansZ gene, encoding a putative L-asparaginase II, was amplified by PCR and expressed in B. subtilis 168 using the shuttle vector pMA5. The activity of the recombinant enzyme was 9.98 U/mL, which was significantly higher than that of B. subtilis B11-06. The recombinant enzyme was purified by a two-step procedure including ammonium sulfate fractionation and hydrophobic interaction chromatography. The optimum pH and temperature of the recombinant enzyme were 7.5 and 40 °C, respectively. The enzyme was quite stable at a pH range of 6.0-9.0 and exhibited about 14.7 and 9.0% retention of activity following 2 h incubation at 50 or 60 °C, respectively. The Km for L-asparagine was 0.43 mM, and the Vmax was 77.51 μM/min. Results of this study also revealed the potential industrial application of this enzyme in reducing acrylamide formation during the potato frying process.