| 20301119 |
Ganguli S, Yoshimoto K, Tomita S, Sakuma H, Matsuoka T, Shiraki K, Nagasaki Y: Improving the Heat Resistance of Ribonuclease A by the Addition of Poly (N,N-diethylaminoethyl methacrylate)-graft-poly (ethylene glycol) (PEAMA-g-PEG). Macromol Biosci. 2010 Mar 18.
Poly (N,N-diethylaminoethyl methacrylate)-graft-poly (ethylene glycol) (PEAMA-g-PEG) has previously been used as a novel additive to improve the heat resistance of lysozyme, which has a positive net charge and a negatively charged active site. In the present study, we show that PEAMA-g-PEG prevents heat inactivation of ribonuclease A (RNase A), which has a positive net charge and a positively charged active site. After treatment at 98 degrees C for 10 min, the enzymatic activity of RNase A complexed with PEAMA-g-PEG was maintained at up to 75% of the level of the native RNase A. The extents of inactivation of RNase A and the complex of RNase A with PEAMA-g-PEG were strongly dependent upon the heating temperature and incubation time. Circular dichroism (CD) spectral analysis revealed that heat-induced irreversible inactivation was largely suppressed when RNase A was complexed with PEAMA-g-PEG. These findings suggest that the heat resistance of RNase A is improved by the external addition of PEAMA-g-PEG. |
11(0,0,1,6) |