L-Asparaginase Purification

Programming Aliphatic Polyester Degradation by Engineered Bacterial Spores

Enzymatic degradation of plastics is a sustainable approach to address the growing issue of plastic accumulation. Here, we demonstrate the degradation of aliphatic polyesters using enzyme-displaying bacterial spores and the fabrication of self-degradable spore-containing plastics. The degradation proceeds without nutrient-dependent spore germination into living cells. Engineered spores completely degrade aliphatic polyesters into small molecules, retain activity through multiple cycles, and regain full activity through germination and sporulation. We also found that the interplay between the glass transition temperature and melting temperature of polyester substrates affects heterogeneous biocatalytic degradation by engineered spores. Directly incorporating spores into polyesters results in robust materials that are completely degradable. Our study offers a straightforward and sustainable biocatalytic approach to plastic degradation.

Review on up and downstream processing of L-asparaginase

L-asparaginase (asparagine amidohydrolase) contributes to 40% of the total enzyme demands worldwide and is one-third of the global requirement as an anti-cancerous drug in treating acute lymphocytic leukemia (ALL), a type of leukemia. This protein breaks down L-asparagine into aspartic acid and ammonia those involved in ALL, rely on for growth and survival. Both non-recombinant and recombinant L-asparaginase can be produced by bacteria when a suitable substrate and method (solid-state fermentation (SSF) or submerged fermentation (SmF) which are techniques to grow microorganisms under controlled conditions), is provided. Between both L-asparaginase's isozymes, asparaginase type II displays higher specific action against L-asparagine and precisely shows antitumor activity. The applied methods in purification of L-asparaginase in the frame of three phases of protein purification strategy known as CIPP (including capture, intermediate purification, and polishing phase) are discussed in this review. Depending on whether the production of the enzyme is intracellular or extracellular, various steps in each phase, like removal of insoluble material, extraction, concentration, and purification, must followed. In this review, authors summarize the upstream processes in L-asparaginase production and the various applied chromatographic and non-chromatographic methods in each step of CIPP, in downstream processes.

Comprehensive insight into exploring the potential of microbial enzymes in cancer therapy: Progress, challenges, and opportunities: A review

Microbial enzymes are crucial catalysts in various industries due to their versatility and efficiency. The microbial enzymes market has recently expanded due to increased demand for many reasons. Among them are eco-friendly solutions, developing novel microbial strains with enhanced enzymes that perform under harsh conditions, providing sustainability, and raising awareness about the benefits of enzyme-based products. By 2030, the global enzyme market is expected to account for $525 billion, with a growth rate of 6.7 %. L-asparaginase and L-glutaminase are among the leading applied microbial enzymes in antitumor therapy, with a growing market share of 16.5 % and 9.5 %, respectively. The use of microbial enzymes has opened new opportunities to fight various tumors, including leukemia, lymphosarcoma, and breast cancer, which has increased their demand in the pharmaceutical and medicine sectors. Despite their promising applications, commercial use of microbial enzymes faces challenges such as short half-life, immunogenicity, toxicity, and other side effects. Therefore, this review explores the industrial production, purification, formulation, and commercial utilization of microbial enzymes, along with an overview of the global enzyme market. With ongoing discoveries of novel enzymes and their applications, enzyme technology offers promising avenues for cancer treatment and other therapeutic interventions.

In vitro and in silico analysis unravelled clinically desirable attributes of Bacillus altitudinis L-asparaginase

AIMS

To identify a marine L-asparaginase with clinically desirable attributes and characterize the shortlisted candidate through in silico tools.

METHODS AND RESULTS

Marine bacterial strains (number = 105) isolated from marine crabs were evaluated through a stepwise strategy incorporating the crucial attributes for therapeutic safety. The results demonstrated the potential of eight bacterial species for extracellular L-asparaginase production. However, only one isolate (Bacillus altitudinis CMFRI/Bal-2) showed clinically desirable attributes, viz. extracellular production, type-II nature, lack of concurrent L-glutaminase and urease activities, and presence of ansZ (functional gene for clinical type). The enzyme production was 22.55 ± 0.5 µM/mg protein/min within 24 h without optimization. The enzyme also showed good activity and stability in pH 7-8 and temperature 37°C, predicting the functioning inside the human body. The Michealis-Menten constant (Km) was 14.75 µM. Detailed in silico analysis based on functional gene authenticating the results of in vitro characterization and predicted the nonallergenic characteristic of the candidate. Docking results proved the higher affinity of the shortlisted candidate to L-asparagine than L-glutamine and urea.

CONCLUSION

Comprehensively, the study highlighted B. altitudinis type II asparaginase as a competent candidate for further research on clinically safe asparaginases.

Enzyme Engineering Strategies for the Bioenhancement of L-Asparaginase Used as a Biopharmaceutical

Over the past few years, there has been a surge in the industrial production of recombinant enzymes from microorganisms due to their catalytic characteristics being highly efficient, selective, and biocompatible. L-asparaginase (L-ASNase) is an enzyme belonging to the class of amidohydrolases that catalyzes the hydrolysis of L-asparagine into L-aspartic acid and ammonia. It has been widely investigated as a biologic agent for its antineoplastic properties in treating acute lymphoblastic leukemia. The demand for L-ASNase is mainly met by the production of recombinant type II L-ASNase from Escherichia coli and Erwinia chrysanthemi. However, the presence of immunogenic proteins in L-ASNase sourced from prokaryotes has been known to result in adverse reactions in patients undergoing treatment. As a result, efforts are being made to explore strategies that can help mitigate the immunogenicity of the drug. This review gives an overview of recent biotechnological breakthroughs in enzyme engineering techniques and technologies used to improve anti-leukemic L-ASNase, taking into account the pharmacological importance of L-ASNase.

Molecular cloning, characterization, and in-silico analysis of l-asparaginase from Himalayan Pseudomonas sp. PCH44

l-Asparaginase (l-ASNase) is a key enzyme used to treat acute lymphoblastic leukemia, a childhood blood cancer. Here, we report on the characterization of a recombinant l-ASNase (Ps44-asn II) from Pseudomonas sp. PCH44. The gene was identified from its genome, cloned, and overexpressed in the host Escherichia coli (E. coli). The recombinant l-ASNase (Ps44-ASNase II) was purified with a monomer size of 37.0 kDa and a homotetrameric size of 148.0 kDa. The purified Ps44-ASNase II exhibited optimum activity of 40.84 U/mg in Tris-HCl buffer (50 mM, pH 8.5) at 45 °C for 15 min. It retained 76.53% of enzyme activity at 45 °C after 120 min of incubation. The half-life and K _d values were 600 min and 1.10 × 10^-3 min^-1, respectively, at 45 °C. The kinetic constants values K _m and V _max were 0.56, 0.728 mM, and 29.41, 50.12 U/mg for l-asparagine and l-glutamine, respectively. However, k _cat for l-glutamine is more (30.91 s^-1) than l-asparagine (18.06 s^-1), suggesting that enzymes act more efficiently on l-glutamine than l-asparagine. The docking analysis of l-asparagine and l-glutamine with active site residues of the enzyme revealed a molecular basis for high l-glutaminase (L-GLNase) activity and provided insights into the role of key amino acid residues in the preferential enzymatic activities.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03224-0.

A potential type-II L-asparaginase from marine isolate Bacillus australimaris NJB19: Statistical optimization, in silico analysis and structural modeling

L-asparaginase is a cardinal biotherapeutic drug for treating acute lymphoblastic leukemia, which is highly prevalent in children worldwide. In the current investigation, L-asparaginase producing marine bacterial isolate, Bacillus australimaris NJB19 (MG734654), was observed to be producing extracellular glutaminase free L-asparaginase (13.27 ± 0.4 IU mL^-1). Production of L-asparaginase was enhanced by the Box-Behnken design approach that enumerated the significant variables affecting the enzyme production. The optimum levels of the derived variables resulted in 2.8-fold higher levels of the enzyme production (37.93 ± 1.06 IU mL^-1). An 1146 bp L-asparaginase biosynthetic gene of Bacillus australimaris NJB19 was identified and cloned in E. coli DH5α, fused with a histidine tag. The in silico analysis of the protein sequence revealed the presence of a signal peptide and classified it as a type II L-asparaginase. Toxic peptide prediction disclosed no toxin domain in the protein sequence, hence suggesting it as a non-toxic protein. The secondary structure analysis of the enzyme displayed a comparable percentage of alpha-helical and random coil structure, while 14.39% and 6.57% of amino acid residues were composed of extended strands and beta-turns, respectively. The functional sites in the three-dimensional structural model of the protein were predicted and interestingly had a few less conserved residues. Bacillus australimaris NJB19 identified in this study produces type-II L-asparaginase, known for its high affinity for asparagine and effectiveness against leukemic cells. Hence, these observations indicate the L-asparaginase, thus obtained, as a potentially significant and novel therapeutic drug.

l-Asparaginase Encapsulation into Asymmetric Permeable Polymersomes

This work reports, for the encapsulation of l-asparaginase, an anticancer enzyme into hybrid PMPC₂₅-PDPA₇₀/PEO₁₆-PBO₂₂ asymmetric polymersomes previously developed by our group, with loading capacities with over 800 molecules per vesicle. Enzyme-loaded polymersomes show permeability and capacity to hydrolyze l-asparagine, which is essential to cancer cells. The nanoreactors proposed in this work can be potentially used in further studies to develop novel therapeutic alternatives based on l-asparaginase.

A comparison of asparaginase activity in generic formulations of E.coli derived L- asparaginase: In-vitro study and retrospective analysis of asparaginase monitoring in pediatric patients with leukemia

AIMS

L-asparaginase is an essential medicine in the treatment of pediatric acute lymphoblastic leukemia (ALL) and the quality of generic formulations is an area of concern. We compared nine generic formulations of L-asparaginase available in India with the innovator.

METHODS

The quality of formulations was assessed by measuring 72-hour trough asparaginase activity in children with ALL during induction following administration of 10,000 IU/m² of L-asparaginase. In-vitro analysis of the label claim was assessed by measuring activity of three generic formulations. Liquid chromatography-mass spectrometry (LC/MS) was used to determine the amount of host contaminant proteins (HCPs) in the formulations.

RESULTS

Between March 2015 to June 2018, 240 samples from 195 patients were analyzed. The number of samples analyzed ranged from 7-66 per generic brand (median: 18) and seven of the innovator. The proportion of generic formulations that failed to achieve a predefined clinical threshold activity of 50 IU/L ranged from 16.7% (2/12) to 84.9% (28/33) in the highest activity to lowest activity generic respectively. On other hand, all innovator samples had activity greater than 50 IU/L. In-vitro asparaginase activity in the three generic formulations tested ranged from 71.4-74.6% of the label claim (10,000 IU) compared to 93.5% for the innovator. LC/MS analysis of generic 5 identified 25 HCPs with a relative peptide count of 27.1% of the total peptides.

CONCLUSIONS

Generic formulations had lower asparaginase activity which raises serious clinical concerns regarding their quality. Until stringent regulatory enforcement improves the quality of these generics, dose adaptive strategies coupled with therapeutic drug monitoring need to be considered.

A comprehensive review on microbial l-asparaginase: Bioprocessing, characterization, and industrial applications

l-Asparaginase (E.C.3.5.1.1.) is a vital enzyme that hydrolyzes l-asparagine to l-aspartic acid and ammonia. This property of l-asparaginase inhibits the protein synthesis in cancer cells, making l-asparaginase a mainstay of pediatric chemotherapy practices to treat acute lymphoblastic leukemia (ALL) patients. l-Asparaginase is also recognized as one of the important food processing agent. The removal of asparagine by l-asparaginase leads to the reduction of acrylamide formation in fried food items. l-Asparaginase is produced by various organisms including animals, plants, and microorganisms, however, only microorganisms that produce a substantial amount of this enzyme are of commercial significance. The commercial l-asparaginase for healthcare applications is chiefly derived from Escherichia coli and Erwinia chrysanthemi. A high rate of hypersensitivity and adverse reactions limits the long-term clinical use of l-asparaginase. Present review provides thorough information on microbial l-asparaginase bioprocess optimization including submerged fermentation and solid-state fermentation for l-asparaginase production, downstream purification, its characterization, and issues related to the clinical application including toxicity and hypersensitivity. Here, we have highlighted the bioprocess techniques that can produce improved and economically viable yields of l-asparaginase from promising microbial sources in the current scenario where there is an urgent need for alternate l-asparaginase with less adverse effects.

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.

Biotechnological production and practical application of L-asparaginase enzyme

L-asparaginase is a vital enzyme of medical importance, and renowned as a chemotherapeutic agent. The relevance of this enzyme is not only limited as an anti-cancer agent, it also possesses a wide range of medical application. The application includes the antimicrobial property, treatment of infectious diseases, autoimmune diseases, canine and feline cancer. Apart from the health care industry, its significance is also established in the food sector as a food processing agent to reduce the acrylamide concentration. L-asparaginase is known to be produced from various bacterial, fungal and plant sources. However, there is a huge market demand due to its wide range of application. Therefore, the industry is still in the search of better-producing source in terms of high yield and low immunogenicity. It can be produced by both submerged and solid state fermentation, and each fermentation process has its own merits and demerits. This review paper focuses on its improved production strategy by adopting statistical experimental optimization techniques, development of recombinant strains, through mutagenesis and nanoparticle immobilization, adopting advanced and cost-effective purification techniques. Available research literature proves the competence and therapeutic potential of this enzyme. Therefore, research orientation toward the exploration of this clinical significant enzyme has to be accelerated. The objectives of this review are to discuss the high yielding sources, current production strategies, improvement of production, effective downstream processing and therapeutic application of L-asparaginase.