title: Micro-Raman spectroscopic observation of water expulsion induced destruction of hydrophobic clusters in crystalline lysozyme.
abstract: In this paper, three kinds of solid lysozyme samples with different water contents were investigated by confocal Raman spectroscopy. For the rod-like lysozyme crystal with highest water content, a sudden decrease of the intensity ratio of the doublet at 1338 and 1360 cm(-1) was observed when the ambient relative humidity (RH) was lower than 86%, indicating the destruction of hydrophobic clusters of lysozyme induced by the expulsion of the hydration water from the crystal. In contrast to the rod-like crystal, tetragonal crystal and floor-like precipitate with a smaller amount of water showed no change of the structures of the hydrophobic clusters when the relative humidity was decreasing. The presence of bulk water in the rod-like crystal is believed a necessary factor for the function of the hydration water which promotes the hydrophobicity of hydrophobic clusters.
authors: Jing-Jing
authors: JJ
authors: Shou
authors: Guang
authors: G
authors: Zeng
authors: Yun-Hong
authors: YH
authors: Zhang
authors: G Q Max
authors: GQ
authors: Lu
mesh_terms: D003460:Crystallization; D057927:Hydrophobic and Hydrophilic Interactions; D009113:Muramidase / Q000737:chemistry* / Q000378:metabolism; D013059:Spectrum Analysis, Raman; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D009113:Muramidase