Faculty Publications
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Item Purification of Glutaminase from Zygosaccharomyces rouxii in Polyethylene Glycol– Sodium Sulphate Aqueous Two-Phase System(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2015) Bolar, S.; Iyyaswami, R.; Belur, P.D.L-glutaminase (EC 3.5.1.2) produced from Zygosaccharomyces rouxii NRRL-Y 2547 was partitioned in an aqueous two phase system comprising PEG 2000 and sodium sulphate. The effects of tie line length (TLL), pH, broth loading (BL), volume ratio, and neutral salt concentration on enzyme partitioning and purification were investigated. The optimal condition for the partitioning of glutaminase was obtained through response surface methodology and obtained the partition coefficient and yield of 12.99 and 95.12%, respectively. The purification factor of 5.59 and selectivity of 6.52 were achieved at the optimal condition. © © Taylor & Francis Group, LLC.Item Partial purification and characterization of L-asparaginase from an endophytic Talaromyces pinophilus isolated from the rhizomes of Curcuma amada(Elsevier, 2016) Krishnapura, P.R.; Belur, P.D.l-Asparaginase is a commercially significant enzyme. There exists a demand for a broad variety of microbial l-asparaginases with characteristics compatible with its different applications. Endophytic microorganisms, in particular are emerging as potential sources of l-asparaginases. The current work involves partial purification and characterization of l-asparaginase from Talaromyces pinophilus, an endophytic fungus isolated from the rhizomes of Curcuma amada. Maximum enzyme activity could be achieved at pH 8.0 and with temperature 28 °C. The enzyme Exhibits 95 % and 98% of its total activity at physiological pH and temperature, respectively. The enzyme activity is largely unhindered in the presence of metal ions such as Ca2+, Cu2+, Fe2+, Mg2+, Mn2+, Zn2+. Increase in the enzyme activity in the presence of thiol groups and reduction in the same upon addition of thiol blockers indicates the involvement of cysteine in the enzyme's catalytic activity. The enzyme is a heterodimer of 62 kDa and 39 kDa. The enzyme has a Km of 6.4 mM, its turnover number towards l-asparagine is 286.3 s-1. The enzyme has 16% glutaminase activity; its Km towards glutamine is 13.3 mM and turnover number is 54.6 s-1. Our results highlight that l-asparaginase from endophytic Talaromyces pinophilus could be considered as potential candidate for clinical and industrial trials, owing to its efficiency and biochemical properties. To the best of our knowledge, this is the first report on partial purification and characterization of L-asparaginase from an endophyte. © 2015 Elsevier B.V. All rights reserved.