UNIVERSITY OF TLEMCEN DEPARTMENT OF BIOLOGY MASTERS:APPLIED BIOCHEMISTRY MECANISMS AND APPLICATION OF ENZYMES REVIEW ARTICLE SUMMARY BY KULE ARNOLD KAHAMBA ARTICLE: DOI: https://doi.org/10.33448/rsd-v10i10.18980 L-ASPARAGINASE APPLICATION IN MEDICINE AND FOOD INTRODUCTION discussing the significance of enzymes, particularly therapeutic enzymes like L-asparaginase, in various fields such as medicine and food industry. Therapeutic enzymes have been developed for clinical use in treatments ranging from anti-inflammatories to cancer drugs. L-asparaginase, for example, is crucial in chemotherapy for lymphoproliferative disorders like acute lymphoblastic leukemia (ALL) by depleting asparagine necessary for the survival of blast cells. Beyond medical use, L-asparaginase is employed in the food industry to mitigate the formation of acrylamide, a potentially carcinogenic compound formed during cooking. Enzyme immobilization, especially using nanoparticulate systems, is a strategy to enhance enzyme reuse and recovery, reducing production costs and environmental impact. However, the process of immobilization can alter enzyme structure and activity, requiring careful evaluation for each application. Overall, L-asparaginase demonstrates significant potential in both medical and food-related contexts, as discussed in various studies. METHODOLOGY We searched for information following a plan made by Souza and others in 2017 and Moher and others in 2009, with a few changes. We looked in different online libraries like Web of Science, Science Direct, SciELO, PubMed, and Scopus. We used specific words related to making and using a substance called L-asparaginase, which is used in different ways, like treating leukemia and reducing a harmful chemical called acrylamide in food. We focused on research that talked about how L-asparaginase works, how it's made, and how it's used, but we didn't include studies that didn't give clear numbers about how much enzyme was made and how well it worked. We also left out studies that used other enzymes instead of L-asparaginase, and those that didn't fully clean or test the enzyme they made. REVIEW OF L-ASPARAGINASE L-asparaginase, also called aminohydrolase, is an enzyme belonging to the amidase group (Kumar & Verma, 2012). It typically exists as a tetramer but can also be found in hexameric, dimeric, or monomeric forms depending on its source. Most bacterial L-asparaginases have quaternary or tertiary structures, with the tetramer consisting of four identical subunits. The work discusses L-asparaginase, an enzyme that catalyzes the hydrolysis of L-asparagine into Laspartic acid and ammonium. It exists in various forms and is found in bacteria, plants, and microorganisms but not in humans. The enzyme's structure and function, including its active site amino acids, are detailed. L-asparaginase is categorized into type I and type II based on enzymatic characteristics. Type II enzymes, particularly, exhibit higher antitumor activity and are used in chemotherapy and the food industry to reduce acrylamide formation. Type II enzymes are tetramers with higher molecular weight, while type I enzymes are homodimers. Despite its therapeutic and industrial applications, type II L-asparaginase can lead to adverse effects such as liver dysfunction, pancreatitis, and central nervous system toxicity. The work underscores the importance of understanding enzyme characteristics for both medical and industrial purposes. THERAPAUTIC APPLICATION L-asparaginase, a therapeutic enzyme, is crucial for treating certain cancers, particularly hematopoietic tumors. It's used in relatively small yet highly pure amounts due to its high kinetics, ensuring efficient enzymatic processes even at low concentrations. Discovered in guinea pig serum, it inhibits tumor growth by depleting the essential amino acid asparagine, vital for cancer cell survival. This depletion starves malignant cells, hindering their growth and inducing apoptosis, while sparing healthy cells, which can synthesize asparagine internally. Despite some tumor cells' resistance due to their own synthesis abilities, L-asparaginase remains a key treatment for pediatric leukemia and specific lymphoma APPLICATION IN FOOD INDUSTRY This part focuses on the utilization of L-asparaginase enzyme in food processing to mitigate the formation of acrylamide, a potentially carcinogenic compound, particularly during thermal processing. This enzyme, primarily of microbial origin, has gained attention due to its ability to catalyze the conversion of asparagine, an amino acid abundant in starchy foods, into aspartic acid and ammonia, thus reducing the precursor for acrylamide formation. The paper discusses the mechanism of acrylamide formation during thermal processing, emphasizing the significance of reducing sugars and asparagine in this process. It highlights various strategies and variables that influence acrylamide formation in foods, including agronomic characteristics, processing methods, and environmental conditions. Additionally, it elucidates alternative pathways for acrylamide formation involving other carbonyl compounds and lipid oxidation products. SOURCES OF ASPARAGINASE Sources of L-asparaginase include various organisms such as animals, plants, and microorganisms, excluding humans. While it is found across different animal and plant groups, microorganisms, including bacteria, fungi, algae, yeasts, and actinomycetes, are preferred due to easier extraction procedures. Enzymatic preparations from plant or animal sources are common but microorganisms are favored for commercial enzyme production due to easier cultivation, manipulation, and selectivity in biosynthesis. Microorganisms can be specifically selected or genetically modified to enhance enzyme production and minimize contaminants. Animal-derived enzymes pose higher risks of contamination and handling complexities. Studies have explored L-asparaginase production from various microorganisms, showcasing differences in kinetic parameters, pH, temperature optima, and stability. Trichoderma viride-produced L-asparaginase exhibits notable characteristics including low Km value, high stability, and compatibility with physiological conditions, making it promising for leukemia treatment. Additionally, L-asparaginase from different microorganisms shows potential for reducing acrylamide in potatoes and exhibiting cytotoxic or anticancer activities against various cancer cell lines, indicating its potential applications in food processing and medical fields. ENZYME IMMOBILISATION Enzyme immobilization, a technique shown to enhance various enzymatic properties like stability, activity, specificity, selectivity, and inhibition reduction, requires careful preparation. For enzyme reuse, the final biocatalyst must exhibit high stability, necessitating stability during the immobilization process itself (Mateo, Palomo & Fernández-Lorente, 2007). Various protocols for enzyme immobilization exist in the literature, based on different chemical interactions like physical adsorption, ionic bonds, covalent bonds, or trapping to link enzymes to different supports. Enzymatic immobilization methods can be categorized based on enzyme-support interactions. ASPARAGINASE IMMOBILISATION L-asparaginase, used in cancer treatment, faces challenges such as immune response, hypersensitivity reactions, and rapid clearance from the body. Its effectiveness in food applications can be hindered by factors like temperature and pH. To address these issues, enzyme immobilization techniques, specifically micro or nanoencapsulation, show promise. Encapsulation offers benefits like enhanced enzyme protection, controlled access to the catalytic center, and improved selectivity. It protects the enzyme from degradation, maintains its activity in circulation, and can guide its action to specific locations. Encapsulation also minimizes adverse conditions that may lead to enzyme denaturation, enhancing drug bioavailability and reducing toxicity. Singh et al. (2020) studied PLGA-encapsulated L-asparaginase in a tumor model. The nanoparticles had a size of 195 nm and showed controlled drug release. In mouse trials, they reduced tumor volume by 51.15% with no toxicity or adverse effects, suggesting their potential for effective tumor treatment CONCLUSION M-asparaginase offers promising therapeutic and food industry applications due to its ability to limit asparagine, thus reducing the formation of carcinogenic compounds like acrylamide in processed foods. However, challenges persist, including the need for enzymes with high activity and stability, evaluation of potential side effects, and the high cost of production and purification. Immobilization techniques show potential in addressing some of these challenges by enhancing enzyme stability and allowing for reuse. Emerging methods like nano and microencapsulation offer further advantages in terms of efficiency and performance. Nonetheless, there remains a gap in research regarding suitable supports for immobilization, particularly for medical and food applications. THANK YOU .
