L-Asparaginase:An Enzyme of Medicinal Value

Enzymes are biocatalysts that are protein in nature , colloidal and thermo labile in character, and specific in their action, synthes ized by living cells. Enzymes have broad range of applications that are widely used in food industry, leather, wool industries, diary industry and medical applications. Many enzymes have been used as drugs; likewise L- asparaginase has been used as anti-tumour agent for the effective treatment of acute lymphoblastic leukemia and as food processing aid t o reduce the formation of acryl amide during frying of starchy foods at high temper ature. It is a naturally occurring intracellular enzyme found in a variety of plants a nd micro-organisms. It is available in three preparations, two of which are native forms p urified from bacterial sources. These include Escherichia coli and Erwinia caratovora , respectively. A third preparation peglyated(PEG)-L-Asparaginase is a chemically modified form of the enzyme in which native E.Coli L-asparaginase has been covalently conjugated to p olyethylene glycol. This enzyme exerts its antitumour activity by deple ting circulating pools of L- asparagine. For pharmacological and clinical tests, microbial sources are best for the bulk production of LA.