Smeller L, Rubens P, Heremans K
Institute of Biophysics, Semmelweis University of Medicine, Budapest, Puskin u. 9 PF 263, H-1444 Hungary.
Biochemistry. 1999 Mar 23;38(12):3816-20. doi: 10.1021/bi981693n.
This work demonstrates that pressure-induced partially unfolded states play a very important role in the aggregation of proteins. The high-pressure unfolding of horse heart metmyoglobin results in an intermediate form that shows a strong tendency to aggregate after pressure release. These aggregates are similar to those that are usually observed upon temperature denaturation. Infrared spectra in the amide I region indicate the formation of an intermolecular antiparallel beta-sheet stabilized by hydrogen bonding. The formation of the aggregates is temperature-dependent. Below 30 degrees C, no aggregation is taking place as seen from the infrared spectra. At 45 and 60 degrees C, two types of aggregates are formed: one that can be dissociated by moderate pressures and one that is pressure-insensitive. When precompressed at 5 degrees C, temperature-induced aggregation takes place at lower temperature (38 degrees C) than without pressure pretreatment (74 degrees C).
这项工作表明，压力诱导的部分解折叠状态在蛋白质聚集过程中起着非常重要的作用。马心高铁肌红蛋白的高压解折叠产生一种中间形式，该中间形式在压力释放后显示出强烈的聚集倾向。这些聚集体类似于通常在温度变性时观察到的聚集体。酰胺I区域的红外光谱表明形成了通过氢键稳定的分子间反平行β-折叠。聚集体的形成取决于温度。从红外光谱可以看出，在30摄氏度以下，没有发生聚集。在45和60摄氏度时，形成两种类型的聚集体：一种可以通过适度压力解离，另一种对压力不敏感。当在5摄氏度下预压缩时，温度诱导的聚集在比没有压力预处理时更低的温度（38摄氏度）下发生。
