Novel glutaminase free L-asparaginase from Nocardiopsis alba NIOT-VKMA08: production, optimization, functional and molecular characterization
| Autor: | Mehmuna Begum, P.S. Dheenan, Gopal Dharani, Nambali Valsalan Vinithkumar, Balakrishnan Meena, Ramalingam Kirubagaran, Lawrance Anburajan |
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| Rok vydání: | 2014 |
| Předmět: |
Stereochemistry
Molecular Sequence Data Bioengineering Biology medicine.disease_cause Glutaminase activity Divalent Substrate Specificity chemistry.chemical_compound Hydrolysis Nocardiopsis alba Glutaminase Species Specificity Enzyme Stability medicine Asparaginase Amino Acid Sequence chemistry.chemical_classification General Medicine Maltose Amino acid Actinobacteria Enzyme Activation Enzyme chemistry Biochemistry Biotechnology |
| Zdroj: | Bioprocess and biosystems engineering. 38(2) |
| ISSN: | 1615-7605 |
| Popis: | Studies were carried out for the optimization and production of novel extracellular glutaminase-free L-asparaginase from Nocardiopsis alba NIOT-VKMA08. Among the tested carbon and nitrogen sources, maximum L-asparaginase production was observed with a combination of L-asparagine and maltose (1.5%) and twofold increase in yield (18.47 IU mL(-1)) was observed with newly optimized NIOT-asparaginase medium. Activity of the purified enzyme was moderately inhibited by various divalent cations and thiol group blocking reagents, with K(m) and V(max) of 0.127 mM and 5.50 U µg(-1). Optimum pH and temperature of purified L-asparaginase for the hydrolysis of L-asparagine was 8.0 and 37 °C, respectively. The enzyme inhibited polyacrylamide formation in 10% solution and it was very specific for its natural substrate L-asparagine. Partial glutaminase activity was not detected, which could reduce the possibility of side effects during cancer therapy. L-Asparaginase biosynthesis gene (ansA) was cloned and transformed in E. coli JM109. The ansA gene sequence reported in this study contains several base substitutions with that of reported sequences in GenBank, resulting in altered amino acid sequences of the translated protein. |
| Databáze: | OpenAIRE |
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