NEW ORLEANS (AP) - A Tulane University scientist has won a four-year, $1.65 million grant for a study he hopes will reveal the molecular basis for diseases such as Alzheimer's and Parkinson's.

The National Institutes of Health grant will allow chemistry Professor Bruce Gibb to study the circumstances under which some salts make some proteins and other substances less water soluble. A salt that increases one protein's solubility may reduce that of another protein, leading to formation of plaques or insoluble buildups.

Gibbs says he hopes understanding that process will help explain "why some proteins go awry and cause diseases like Parkinson's and Alzheimer's." He says the long-term aim is finding the underlying causes of such diseases but cautions that's a long way down the road.