H-1-NMR and Raman studies on perforating trauma-induced cataract formationin a mouse lens

In order to provide new insight into the molecular mechanism of perforating trauma-induced cataract formation in an 8-week-old ddY mouse lens, we perf ormed an in situ investigation into changes in the water-protein and/or pro tein-protein interactions by using 500 MHz H-1-NMR spectroscopy, and into s tructural alterations in lens proteins by using Raman spectroscopy. Cross-r elaxation times of water protons in the perforated opaque lens were conside rably shorter than those in the intact transparent lens, whereas there was no significant difference in water content, suggesting a drastic change in water-protein and protein-protein interactions in the perforated lens. In a ddition, there was no significant difference in the intensity ratios of sev eral key Raman bands between intact and perforated lenses, indicating that no significant local and overall conformational changes in lens protein its elf occur in the perforated lens. The present H-1-NMR and Raman results lea d us to the conclusion that changes leading to lens opacification in the pe rforating trauma-induced cataract appear to involve the rapid formation of immobile large lens protein aggregates without formation of intra- and inte rmolecular disulfide linkages, and rapid increase in a fraction of bound wa ter associated with large protein aggregates. (C) 2000 Elsevier Science B.V . All rights reserved.