Optimization of monomethoxy polyethyleneglycol-modified oxalate decarboxylase by response surface methodology

• Published in: Journal of biological physics Vol. 43; no. 3; pp. 445 - 459
• Main Authors: Long, Han, Cai, XingHua, Yang, Hui, He, JunBin, Wu, Jia, Lin, RiHui
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2017; Springer Nature B.V
• Subjects: Biochemistry; Biological and Medical Physics; Biophysics; Carboxy-Lyases - chemistry; Carboxy-Lyases - metabolism; Complex Fluids and Microfluidics; Complex Systems; Enzyme Stability; Fourier transforms; Gel electrophoresis; Hydrogen-Ion Concentration; Infrared spectroscopy; Kinetics; Neurosciences; Optimization; Original Paper; Oxalate decarboxylase; Oxalic acid; pH effects; Physics; Physics and Astronomy; Polyethylene glycol; Polyethylene Glycols - chemistry; Research methodology; Sodium lauryl sulfate; Soft and Granular Matter; Surface chemistry; Temperature; Temperature effects; Thermal stability; Trypsin; Trypsin - metabolism; Response surface method (RSM); Monomethoxy polyethyleneglycol; Oxalate decarboxylase
• ISSN: 0092-0606; 1573-0689; 1573-0689
• DOI: 10.1007/s10867-017-9461-8

In order to improve the stability of oxalate decarboxylase (Oxdc), response surface methodology (RSM), based on a four-factor three-level Box-Behnken central composite design was used to optimize the reaction conditions of oxalate decarboxylase (Oxdc) modified with monomethoxy polyethyleneglycol (mPEG5000). Four independent variables such as the ratio of mPEG-aldehyde to Oxdc, reaction time, temperature, and reaction pH were investigated in this work. The structure of modified Oxdc was identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared (FTIR) spectroscopy, the stability of the modified Oxdc was also investigated. The optimal conditions were as follows: the mole ratio of mPEG-aldehyde to Oxdc of 1:47.6, time of 13.1 h, temperature at 29.9 °C, and the reaction pH of 5.3. Under optimal conditions, experimental modified rate (MR = 73.69%) and recovery rate (RR = 67.58%) were matched well with the predicted value (MR = 75.11%) and (RR = 69.17%). SDS-PAGE and FTIR analysis showed that mPEG was covalently bound to the Oxdc. Compared with native Oxdc, the modified Oxdc (mPEG-Oxdc) showed higher thermal stability and better tolerance to trypsin or different pH treatment. This work will provide a further theoretical reference for enzyme modification and conditional optimization.