Purification, characterization and amino acid content of cholesterol oxidase produced by Streptomyces aegyptia NEAE 102

BMC Microbiology

Research Article

Nehal M. El-Deeb¹  Nancy M. El-Shweihy²  Noura El-Ahmady El-Naggar²  Hoda M. Soliman³  Sahar F. Deraz⁴ 

[1] Biopharmacetical Product Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt;Department of Bioprocess Development, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt;Department of Botany, Faculty of Science, Mansoura University, Mansoura, Egypt;Department of Protein Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research & Technological Applications, Alexandria, Egypt;

关键词: Streptomyces aegyptia;    Cholesterol oxidase;    Purification;    DEAE Sepharose CL-6B;    Characterization;    Molecular weight;    Amino acid contents;   

DOI  :  10.1186/s12866-017-0988-4

 received in 2016-12-24, accepted in 2017-03-21,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThere is an increasing demand on cholesterol oxidase for its various industrial and clinical applications. The current research was focused on extracellular cholesterol oxidase production under submerged fermentation by a local isolate previously identified as Streptomyces aegyptia NEAE 102. The crude enzyme extract was purified by two purification steps, protein precipitation using ammonium sulfate followed by ion exchange chromatography using DEAE Sepharose CL-6B. The kinetic parameters of purified cholesterol oxidase from Streptomyces aegyptia NEAE 102 were studied.ResultsThe best conditions for maximum cholesterol oxidase activity were found to be 105 min of incubation time, an initial pH of 7 and temperature of 37 °C. The optimum substrate concentration was found to be 0.4 mM. The higher thermal stability behavior of cholesterol oxidase was at 50 °C. Around 63.86% of the initial activity was retained by the enzyme after 20 min of incubation at 50 °C. The apparent molecular weight of the purified enzyme as sized by sodium dodecyl sulphate-polyacryalamide gel electrophoresis was approximately 46 KDa. On DEAE Sepharose CL-6B column cholesterol oxidase was purified to homogeneity with final specific activity of 16.08 U/mg protein and 3.14-fold enhancement. The amino acid analysis of the purified enzyme produced by Streptomyces aegyptia NEAE 102 illustrated that, cholesterol oxidase is composed of 361 residues with glutamic acid as the most represented amino acid with concentration of 11.49 μg/mL.ConclusionsTaking into account the extracellular production, wide pH tolerance, thermal stability and shelf life, cholesterol oxidase produced by Streptomyces aegyptia NEAE 102 suggested that the enzyme could be industrially useful.

【 授权许可】

CC BY   
© The Author(s). 2017