PRESSURE-INDUCED PROTEIN GLASS TRANSITION AND WATER-PROTEIN INTERACT

点击翻译按钮获取中文摘要

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Proteins undergo the `glass transition`, a transition in protein dynamics, when subjected to temperature variation. This protein glass transition is highly correlated with protein function. A protein molecule ceases to perform its biological function at temperatures below the glass transition points. Therefore, studying the protein glass transition may provide insight to the correlation between protein dynamics and function. It is speculated that the water surrounding a protein molecule plays an important role in inducing protein glass transition. However, the exact mechanism is still an open question. Recently, researchers proposed a probable mechanism involving the phase transition of water, high density liquid (HDL) and low density liquid (LDL) water transition. Given the controversy over the existence of HDL and LDL water, this proposed mechanism demands more experimental scrutiny. In our study, we propose to utilize the high pressure protein crystallography technique and synchrotron radiation to study the protein glass transition. Varying pressure levels will be applied to protein crystals of bovine pancreatic ribonuclease A while the structure is measured at CHESS. The crystallography results will provide both the static structure and dynamics of the protein and surrounding water versus pressure. The dependence of the protein glass transition and water dynamics as well as their structure upon pressure may provide precious information about the interplay among water, protein dynamics, protein structure and protein function.