Purification and Characterization of Asparaginase from Phaseolus vulgaris Seeds

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.

Immobilization of l-asparaginase on genipin cross-linked chitosan beads shows better acrylamide diminution in cassava chips: Process optimization and characterization

Glutaraldehyde is the conventionally used cross-linker for the activation and cross-linking of support matrices used in enzyme immobilization. However, the toxic nature of glutaraldehyde makes it unsafe for food applications, propelling the need for nontoxic cross-linkers. Genipin reacts with the primary and secondary amines generating a dark-blue colored pigment and is an attractive alternative to glutaraldehyde as a cross-linker for enzyme immobilization. Apart from its excellent cross-linking properties, genipin possesses added advantages over glutaraldehyde such as proven health benefits, biocompatibility, and biodegradability. The present study explores the application of chitosan beads cross-linked with the natural and nontoxic agent, genipin, for immobilizing l-asparaginase, aimed at its subsequent use in mitigating acrylamide formation in food products. The immobilized l-asparaginase exhibited improved functionalities such as stability, reusability, and reduction in acrylamide formation in deep-fried cassava chips. One of the limitations observed during application in the food process was the mechanical fragility of the chitosan beads during speedy stirring. This can be overcome by increasing the concentration and time of contact of the coagulant bath during the formation of chitosan beads. The drying of the enzyme-bound chitosan beads will also lead to shrinkage and prevent breakage during stirring. This study conclusively demonstrated the applicability of immobilizing l-asparaginase on genipin cross-linked chitosan beads in food-related processes.

Kinetics characterization of a low immunogenic recombinant l-asparaginase from Phaseolus vulgaris with cytotoxic activity against leukemia cells

l-asparaginases play a crucial role in the treatment of acute lymphoblastic leukemia (ALL), a type of cancer that mostly affects children and teenagers. However, it is common for these molecules to cause adverse reactions during treatment. These downsides ignite the search for novel asparaginases to mitigate these problems. Thus, this work aimed to produce and characterize a recombinant asparaginase from Phaseolus vulgaris (Asp-P). In this study, Asp-P was expressed in Escherichia coli with high yields and optimum activity at 40 °C, pH 9.0. The enzyme Km and Vmax values were 7.05 mM and 1027 U/mg, respectively. Asp-P is specific for l-asparagine, showing no activity against l-glutamine and other amino acids. The enzyme showed a higher cytotoxic effect against Raji than K562 cell lines, but only at high concentrations. In silico analysis indicated that Asp-P has lower immunogenicity than a commercial enzyme. Asp-P induced biofilm formation by Candida sp. due to sublethal dose, showing an underexplored potential of asparaginases. The absence of glutaminase activity, lower immunogenicity and optimal activity similar to physiological temperature conditions are characteristics that indicate Asp-P as a potential new commercial enzyme in the treatment of ALL and its underexplored application in the treatment of other diseases.

Optimization and characterization of antileukemic L-asparaginase produced by Fusarium solani endophyte

L-asparaginase is an antileukemic enzyme that hydrolyzes L-asparagine into L-aspartic acid and ammonia, causing cell starvation and apoptosis in susceptible leukemic cell populations. Currently, L-asparaginase obtained from bacterial sources is constrained by several issues, including lesser productivity, stability, selectivity, and higher toxicity. The goal of this study is to provide fungal L-asparaginase with in-vitro effectiveness towards different human carcinomas. L-asparaginase from endophytic Fusarium solani (Gene Bank accession number MW209717) isolated from the roots of the medicinal plant Hedera helix L. was characterized and optimized experimentally for maximum L-asparaginase production in addition to evaluating its subsequent cytotoxicity towards acute monocytic leukemia and human skin fibroblast cell lines. The enzyme production was maximized using potato dextrose media (15.44 IU/ml/hr) at the 5th and 6th days of fermentation with incubation temperature 30 °C, 3% asparagine, 150-180 rpm agitation rate and a 250 ml flask. Enzyme characterization studies revealed that the enzyme maintained its thermal stability with temperatures up to 60 °C. However, its optimal activity was achieved at 35 °C. On measuring the enzymatic activity at various temperatures and different pH, maximum enzyme activity was recorded at 40 °C and pH 8 using 0.1 M asparagine concentration. Results also revealed promising cytotoxic activity against acute monocytic leukemia with IC50 = 3.66 µg/ml and low cytotoxicity against tested normal human skin fibroblast cell line which suggested that it might have selective toxicity, and consequently it could be used as a less toxic alternative to the current formulations.

Clinical impacts of the concomitant use of L-asparaginase and total parenteral nutrition containing L-aspartic acid in patients with acute lymphoblastic leukemia

Introduction

L-asparaginase (ASNase) depletes L-asparagine and causes the death of leukemic cells, making it a mainstay for the treatment of acute lymphoblastic leukemia (ALL). However, ASNase's activity can be inhibited by L-aspartic acid (Asp), which competes for the same substrate and reduces the drug's efficacy. While many commercially used total parenteral nutrition (TPN) products contain Asp, it is unclear how the concomitant use of TPNs containing Asp (Asp-TPN) affects ALL patients treated with ASNase. This propensity-matched retrospective cohort study evaluated the clinical effects of the interaction between ASNase and Asp-TPN.

Methods

The study population included newly diagnosed adult Korean ALL patients who received VPDL induction therapy consisting of vincristine, prednisolone, daunorubicin, and Escherichia coli L-asparaginase between 2004 and 2021. Patients were divided into two groups based on their exposure to Asp-TPN: (1) Asp-TPN group and (2) control group. Data, including baseline characteristics, disease information, medication information, and laboratory data, were collected retrospectively. The primary outcomes for the effectiveness were overall and complete response rates. Relapse-free survival at six months and one year of treatment were also evaluated. The safety of both TPN and ASNase was evaluated by comparing liver function test levels between groups. A 1:1 propensity score matching analysis was conducted to minimize potential selection bias.

Results

The analysis included a total of 112 ALL patients, and 34 of whom received Asp-TPN and ASNase concomitantly. After propensity score matching, 30 patients remained in each group. The concomitant use of Asp-TPN and ASNase did not affect the overall response rate (odds ratio [OR] 0.53; 95% confidence interval [CI] = 0.17–1.62) or the complete response rate (OR 0.86; 95% CI = 0.29–2.59) of the ASNase-including induction therapy. The concomitant use of Asp-TPN and ASNase also did not impact relapse-free survival (RFS) at six months and one year of treatment (OR 1.00; 95% CI = 0.36–2.78 and OR 1.24; 95% CI, 0.50–3.12, respectively). The peak levels of each liver function test (LFT) and the frequency of LFT elevations were evaluated during induction therapy and showed no difference between the two groups.

Conclusion

There is no clear rationale for avoiding Asp-TPN in ASNase-treated patients.

Immobilization and Characterization of L-Asparaginase over Carbon Xerogels

L-asparaginase (ASNase) is an aminohydrolase currently used in the pharmaceutical and food industries. Enzyme immobilization is an exciting option for both applications, allowing for a more straightforward recovery and increased stability. High surface area and customizable porosity make carbon xerogels (CXs) promising materials for ASNase immobilization. This work describes the influence of contact time, pH, and ASNase concentration on the immobilization yield (IY) and relative recovered activity (RRA) using the Central Composite Design methodology. The most promising results were obtained using CX with an average pore size of 4 nm (CX-4), reaching IY and RRA of 100%. At the optimal conditions (contact time 49 min, pH 6.73, and [ASNase] 0.26 mg·mL⁻¹), the ASNase-CXs biocomposite was characterized and evaluated in terms of kinetic properties and operational, thermal, and pH stabilities. The immobilized ASNase onto CX-4 retained 71% of its original activity after six continuous reaction cycles, showed good thermal stability at 37 °C (RRA of 91% after 90 min), and was able to adapt to both acidic and alkaline environments. Finally, the results indicated a 3.9-fold increase in the immobilized ASNase affinity for the substrate, confirming the potential of CXs as a support for ASNase and as a cost-effective tool for subsequent use in the therapeutic and food sectors.

Plant asparaginase versus microbial asparaginase as anticancer agent

The considerable effect of enzymes on human health draws great attention to enzyme-based drugs (therapeutic enzymes), in recent times. L-asparaginase (ASNase) is a well-known therapeutic enzyme. It has varied applications and is a single molecule for the treatment of multiple diseases. This study tries to extract asparaginase from soybean debris (agricultural wastes) as a cheap plant source and compare this with microbial asparaginase as an agent in cancer chemotherapy. The asparaginase was extracted and purified from soybean debris (plant asparaginase) and Pseudomonas aeruginosa (microbial asparaginase), then the physiochemical characters were determined for the two enzymes, and the anticancer activity of plant and microbial asparaginase was determined against gastric cancer (CLS-145), pancreatic cancer (AsPC-1), colon cancer (HCT116), esophagus cancer (KYSE-410), liver cancer (HepG2), breast cancer (MCF-7), and cervical cancer (HELLA). The results showed that plant asparaginase was superior to microbial asparaginase in its physiochemical characters. Plant asparaginase showed higher stability and activity under the conditions of changing either the temperature or the pH; also plant asparaginase has a higher affinity to the asparagine than the microbial asparaginase; besides, this plant asparaginase did not show activity with glutamine as a substrate. The plant asparaginase showed higher anticancer activity than that of microbial asparaginase against all studied cancer cell lines. The present study introduces as the first time a comparative study between the plant and microbial asparaginase which proves that soybean debris asparaginase can be more efficient and safe than that of the microbial asparaginase as an anticancer agent.

Purification and characterization of L-asparaginase extracted from local Iraqi green beans (Phaseoulus vulgaris)

The most prevalent metabolite for the storage and transport of nitrogen used in protein production is L-asparagine; in earlier studies, L-asparaginase enzyme derived from microorganisms was utilized to treat cancer cells; therefore, this study aimed to purify and describe this enzyme derived from Iraqi green bean seeds rather than microbial sources. The enzymes were partially purified from green beans by short steps, including centrifugation of crude enzyme, dialysis by Diethylaminoethyl Sepharose Column, and equilibrated using 20 mM Tris-HCl buffer, pH 8.0, and then applied to a sephacryl S-200. Coulometric methods measured the enzymatic activity at 450 nm, and the unit of activity was calculated by comparing it to a standard curve. Purification of L-asparaginase yielded a 5 percent yield, a 2.7 fold increase in activity, and a 43 unit/ml activity. The pH of asparaginase was optimal at 8.0. After a one-day incubation period, this enzyme became more stable at pH levels ranging from 7.5 to 9.5. This enzyme had the same optimal temperature and thermal stability at 40°C, but it was more stable at temperatures ranging from 20 to 40°C, allowing it to retain its maximal activity.

Characterization of novel L-asparaginases having clinically safe profiles from bacteria inhabiting the hemolymph of the crab, Scylla serrata (Forskål, 1775)

L-asparaginase (ASNase) is the principal chemotherapeutic agent against different blood cancers. The risks associated with current clinical preparations demand screening for novel ASNases. Accordingly, the study was conducted to shortlist ASNases having clinically safer profiles from a novel niche, namely, microbes in the gut and hemolymph of apparently healthy Scylla serrata. A four-step strategic approach incorporating the essential requirements for clinically safer profiles was followed. The initial step through plate assay showed five (9.61%) potential ASNase producers. The relative prevalence of ASNase producers was higher in hemolymph (13.33%) than gut (4.5%). The positive isolates were identified as Priestia aryabhattai, Priestia megaterium, Bacillus altitudinis, Shewanella decolorationis, and Chryseomicrobium amylolyticum. Quantitative profiles revealed high ASNase production (114.29 to 287.36 U/mL) without any optimization, with an added advantage of the extracellular production. The second step for substrate specificity studies revealed the absence of L-glutaminase and urease activities in ASNases from C. amylolyticum and P. megaterium, the most desirable properties for safe clinical applications. This is the first report of glutaminase and urease-free ASNase from these two bacteria. The third step ensured type II nature of selected ASNases, the targeted form in clinical applications. The fourth step confirmed the activity and stability in human physiological conditions. Altogether, the results revealed two potential ASNases with clinically compatible profiles.

Insights into Asparaginase from Endophytic Fungus Lasiodiplodia theobromae: Purification, Characterization and Antileukemic Activity

Endobiotic fungi are considered as a reservoir of numerous active metabolites. Asparaginase is used as an antileukemic drug specially to treat acute lymphoblastic leukaemia. The presented study aims to optimize the media conditions, purify, characterize, and test the antileukemic activity of the asparaginase induced from Lasiodiplodia theobromae. The culture medium was optimized using an experiment designed by The Taguchi model with an activity ranging from 10 to 175 IU/mL. Asparaginase was induced with an activity of 315 IU/mL. Asparaginase was purified with a specific activity of 468.03 U/mg and total activity of 84.4 IU/mL. The purified asparaginase showed an approximate size of 70 kDa. The purified asparaginase showed an optimum temperature of 37 °C and an optimum pH of 6. SDS reduced the activity of asparaginase to 0.65 U/mL while the used ionic surfactants enhanced the enzyme activity up to 151.92 IU/mL. The purified asparaginase showed a K_m of 9.37 µM and V_max of 127.00 µM/mL/min. The purified asparaginase showed an IC₅₀ of 35.2 ± 0.7 IU/mL with leukemic M-NFS-60 cell lines and CC₅₀ of 79.4 ± 1.9 IU/mL with the normal WI-38 cell line. The presented study suggests the use of endophytic fungi as a sustainable source for metabolites such as asparaginase, provides an opportunity to develop a facile, eco-friendly, cost-effective, and rapid synthesis of antileukemic drugs, which have the potential to be used as alternative and reliable sources for potent anticancer agents.

Central Carbon Metabolism, Sodium-Motive Electron Transfer, and Ammonium Formation by the Vaginal Pathogen Prevotella bivia

Replacement of the Lactobacillus dominated vaginal microbiome by a mixed bacterial population including Prevotella bivia is associated with bacterial vaginosis (BV). To understand the impact of P. bivia on this microbiome, its growth requirements and mode of energy production were studied. Anoxic growth with glucose depended on CO₂ and resulted in succinate formation, indicating phosphoenolpyruvate carboxylation and fumarate reduction as critical steps. The reductive branch of fermentation relied on two highly active, membrane-bound enzymes, namely the quinol:fumarate reductase (QFR) and Na⁺-translocating NADH:quinone oxidoreductase (NQR). Both enzymes were characterized by activity measurements, in-gel fluorography, and VIS difference spectroscopy, and the Na⁺-dependent build-up of a transmembrane voltage was demonstrated. NQR is a potential drug target for BV treatment since it is neither found in humans nor in Lactobacillus. In P. bivia, the highly active enzymes L-asparaginase and aspartate ammonia lyase catalyze the conversion of asparagine to the electron acceptor fumarate. However, the by-product ammonium is highly toxic. It has been proposed that P. bivia depends on ammonium-utilizing Gardnerella vaginalis, another typical pathogen associated with BV, and provides key nutrients to it. The product pattern of P. bivia growing on glucose in the presence of mixed amino acids substantiates this notion.

Purification and anticancer activity of glutaminase and urease-free l-asparaginase from novel endophyte Chaetomium sp

l-Asparaginase catalyzes the hydrolysis of asparagine into aspartic acid and ammonia. The present work elaborates the isolation and identification of a novel endophytic fungal isolate producing l-glutaminase and urease-free l-asparaginase. Cell growth and enzyme production were investigated for large production. The isolated endophytic fungi were identified at molecular levels and a phylogenetic tree was constructed. The enzyme synthesis was evaluated by cultivating the isolated microorganisms in potato dextrose agar medium. Out of 27 isolated endophytes, nine were producing "l-glutaminase and urease-free l-asparaginase." l-Asparaginase from Chaetomium sp. exhibited superior enzyme activity than from the other isolates. Observed optimal conditions for l-asparaginase activity were 25 min of incubation time, 0.5 mg of enzyme source, 40°C of temperature, and pH 7.0. l-Asparaginase from Chaetomium sp. exhibited anticancer activity on human blood cancer (MOLT-4) cells. The current study has demonstrated the production of contaminant-free l-asparaginase enzyme from endophytic fungal species. The results showed that: (a) maximum enzyme activity was observed for l-asparaginase from Chaetomium sp., (b) concentration of glucose in the medium as a carbon source suppressed the enzyme production. Chaetomium sp. is a novel source for "l-glutaminase and urease-free l-asparaginase," which may play a major role in pharmacotherapy.

Bioprocess Optimization of Nutritional Parameters for Enhanced Anti-leukemic L-Asparaginase Production by Aspergillus candidus UCCM 00117: A Sequential Statistical Approach

Sequential optimization of bioprocess nutritional conditions for production of glutaminase-near-free L-asparaginase by Aspergillus candidus UCCM 00117 was conducted under shake flask laboratory conditions. Catalytic and anti-cancer activities of the poly-peptide were evaluated using standard in vitro biochemical methods. Medium nutrients were selected by one-factor-at-a-time (OFAT) approach while Plackett-Burman design (PBD) screened potential factors for optimization. Path of steepest ascent (PSA) and response surface methodology (RSM) of a Min-Run-Res V fractional factorial of a central composite rotatable design (CCRD) were employed to optimize factor levels towards improved enzyme activity. A multi-objective approach using desirability function generated through predictor importance and weighted coefficient methodology was adopted for optimization. The approach set optimum bioprocess conditions as 49.55 g/L molasses, 64.98% corn steep liquor, 44.23 g/L asparagine, 1.73 g/L potassium, 0.055 g/L manganese and 0.043 g/L chromium (III) ions, at a composite desirability of 0.943 and an L-asparaginase activity of 5216.95U. The Sephadex-200 partially-purified polypeptide had a specific activity of 476.84 U/mg; 0.087U glutaminase activity, 36.46% yield and 20-fold protein purification. Anti-cancer activity potentials of the catalytic poly-peptide were dose-dependent with IC₅₀ (µg/mL): 4.063 (HL-60), 13.75 (HCT-116), 15.83 (HeLa), 11.68 (MCF-7), 7.61 (HepG-2). The therapeutic enzyme exhibited 15-fold more cytotoxicity to myeloid leukemia cell line than to normal (HEK 238 T) cell. Optimum temperature and pH for activity were within physiological range. However, significant interactions between exposure time and levels of each of temperature and pH made interpretations of residual enzyme activities difficult. The manganese-dependent L-asparaginase from Aspergillu s candidus UCCM 00117 is recommended for further anticancer drug investigations.

Constitutive expression of Asparaginase in Gossypium hirsutum triggers insecticidal activity against Bemisia tabaci

Whitefly infestation of cotton crop imparts enormous damage to cotton yield by severely affecting plant health, vigour and transmitting Cotton Leaf Curl Virus (CLCuV). Genetic modification of cotton helps to overcome both the direct whitefly infestation as well as CLCuV based cotton yield losses. We have constitutively overexpressed asparaginase (ZmASN) gene in Gossypium hirsutum to overcome the cotton yield losses imparted by whitefly infestation. We achieved 2.54% transformation efficiency in CIM-482 by Agrobacterium-mediated shoot apex transformation method. The relative qRT-PCR revealed 40-fold higher transcripts of asparaginase in transgenic cotton line vs. non-transgenic cotton lines. Metabolic analysis showed higher contents of aspartic acid and glutamic acid in seeds and phloem sap of the transgenic cotton lines. Phenotypically, the transgenic cotton lines showed vigorous growth and height, greater number of bolls, and yield. Among six representative transgenic cotton lines, line 14 had higher photosynthetic rate, stomatal conductance, smooth fiber surface, increased fiber convolutions (SEM analysis) and 95% whitefly mortality as compared to non-transgenic cotton line. The gene integration analysis by fluorescence in situ hybridization showed single copy gene integration at chromosome number 1. Collectively, asparaginase gene demonstrated potential to control whitefly infestation, post-infestation damages and improve cotton plant health and yield: a pre-requisite for farmer's community.

L-Asparaginase Isolated from Phaseolus vulgaris Seeds Exhibited Potent Anti-Acute Lymphoblastic Leukemia Effects In-Vitro and Low Immunogenic Properties In-Vivo

Escherichia coli-derived L-asparaginases have been used in the treatment of acute lymphoblastic leukemia (ALL), however, clinical hypersensitivity reactions and silent inactivation due to antibodies against E. coli-asparaginase, lead to inactivation of these preparations in most cases.Therefore, this study was aimed to investigate the cytotoxicity and antitumor effects ofa novel L-asparaginaseenzyme, isolated from Phaseolus vulgaris seeds (P-Asp) on the ALL cell line (Jurkat). The immunogenicity of the enzyme was also evaluated in-vivo and results were compared to commercially available enzymes of microbial sources. The data demonstrated that P-Asp has an enhanced anti-proliferative effect on ALL cells as detected by the WST-8 cell viability assay kit. Cells treated with P-Asp also exhibited a higher degree of early apoptosis compared with asparaginase from Escherichia coli (L-Asp) or its pegylated form Pegasparagas (PEG-ASP) that induced higher rates of late apoptosis and necrosis as detected by an Annexin V/Propidium iodide binding assay. In-vivo experiments indicated that mice treated with P-Asp had less distinct allergenic responses than other bacterial enzyme preparations as indicated by lower serum concentrations of IgG, IgE, IgM and mMCP-1 compared with other treated groups. In conclusion, P-Asp can be considered as a promising candidate for use in the treatment of ALL.