Kar Karunakar, Kishore Nand
Indian Institute of Technology-Bombay, Powai, Mumbai, India.
Biopolymers. 2007;87(5-6):339-51. doi: 10.1002/bip.20834.
A combination of spectroscopic, calorimetric, and microscopic studies to understand the effect of hydroxyproline on the thermal stability, conformation, biological activity, and aggregation of proteins has been investigated. Significantly increased protein stability and suppression of aggregation is achieved in the presence of hydroxyproline. For example, exceptional increase in the thermal stability of lysozyme up to 26.4 degrees C and myoglobin up to 31.8 degrees C is obtained in the presence of hydroxyproline. The increased thermal stability of the proteins is observed to be accompanied with significant rise of the catalytic activity. Hydroxyproline is observed to prevent lysozyme fibril formation in vitro. Fluorescence and circular dichroism studies indicate induction of tertiary structures of the studied proteins in the presence of hydroxyproline. Preferential hydration of the native state is found to be crucial for the mechanism of protein stabilization by hydroxyproline. We compared the effect of hydroxyproline to that of proline and observed similar increase in the activity and suppression of protein aggregation. The results demonstrate the use of hydroxyproline as a protein stabilizer and in the prevention of protein aggregation and fibril formation.
为了了解羟脯氨酸对蛋白质热稳定性、构象、生物活性和聚集的影响，研究人员进行了光谱、量热和显微镜研究的组合。在羟脯氨酸存在的情况下，蛋白质稳定性显著提高，聚集受到抑制。例如，在羟脯氨酸存在的情况下，溶菌酶的热稳定性异常提高了26.4摄氏度，肌红蛋白的热稳定性提高了31.8摄氏度。观察到蛋白质热稳定性的提高伴随着催化活性的显著上升。在体外，羟脯氨酸可防止溶菌酶原纤维的形成。荧光和圆二色性研究表明，在羟脯氨酸存在的情况下，所研究蛋白质的三级结构会被诱导。发现天然状态的优先水合作用对于羟脯氨酸稳定蛋白质的机制至关重要。我们将羟脯氨酸的作用与脯氨酸的作用进行了比较，观察到活性有类似的增加，且蛋白质聚集受到抑制。结果表明羟脯氨酸可作为蛋白质稳定剂，用于预防蛋白质聚集和原纤维形成。
