ABSTRACT
L-Asparaginase (EC 3.5.1.1) a wide spread enzyme can be found in many microbes like Aerobacter, Bacillus, Pseudomonas, Serratia, Xanthomonas, Photobacterium [1], Streptomyces [2], Proteus [3], Vibrio [4], and Aspergillus [5], etc., The medically important enzyme hydrolyze L-asparagine (an essential amino acid) to aspartic acid and ammonia. For protein synthesis in many types of cancer cells L-asparagine is essential and they are deprived of L-asparagine in presence of L-Asparaginase, thus resulting in cytotoxicity of tumor cells. All L-Asparaginase do not possess antitumor properties which seem to be related to the affinity of the enzyme for the substrate and factors affecting the clearance rate from the system [6]. Particularly against acute lymphoblastic leukemia LAsparaginase from E. coli and Erwinia carotovora possess antitumor activity [7]. But, administering such enzyme protein for long duration generally produces the corresponding antibody in the tissues, resulting in anaphylactic shock and may neutralize the drug effect. So, there is a need for the search of new serologically different L-Asparaginase with similar therapeutic effect is highly desired. The present study is aimed at homology modeling of 3-D Structure of L-Asparaginase from Enterobacter Aerogenes KCTC2190 using Swiss-Model [8-10]. The constructed model was further validated by Ramachandran plot. The model was again refined and subjected to energy minimization using CHIRON server and evaluated for quality assessment. Chiron performs rapid energy minimization of protein molecules using discrete molecular dynamics with an all-atom representation for each residue in the protein.
