Confocal Raman Study on Dehydration Process of Insulin Crystals

摘要

It is well-known that water is one of the most important elements of life and is indispensable to biological systems. Only in aqueous environment can biomolecules such as proteins and nucleic acids maintain their unique structures and normally perform their biological fuctions.1 Among all the interactions between water and biological macromolecules, hydrogen bonding is undoubtedly the most important one. In solution, water around protein molecules can be generally classified into three categories, that is internal water which occupy the cavities and clefts inside protein molecules and interact strongly with protein molecules; hydration water which interact directly with the hydrophilic residues exposed on the surface of the macromolecules; and bulk water.2 In protein crystal, because there is no stable location for water molecules, bulk water can be hardly observed, while bound water is mainly preserved as an integral part of the crystal structure.