WEST LAFAYETTE, Ind. -- A molecule designed by a Purdue University researcher could lead to the first drug treatment for Alzheimer's disease.

"There are many people suffering, and no effective treatment is available to them," said Arun Ghosh, the Purdue professor who designed the molecule. "There is an urgent need for a drug to treat this devastating disease, and the scientific community has been working on this problem for many years."

The National Institute on Aging estimates that as many as 4.5 million Americans suffer from Alzheimer's disease, which leads to dementia by affecting parts of the brain that control thought, memory and language.

The new molecule prevents the first step in a chain of events that leads to amyloid plaque formation in the brain. The material at various stages of plaque formation is made up of fibrous clumps of toxic proteins that cause the devastating symptoms of Alzheimer's disease, said Ghosh, who has a dual appointment in the chemistry and medicinal chemistry and molecular pharmacology departments.

"Interdisciplinary research and the tools available today allowed us to build a molecule that is both highly potent and highly selective, meaning it does not affect other enzymes important to brain function," he said.

Jordan Tang, head of the Protein Studies Research Program at the Oklahoma Medical Research Foundation, is one of the discoverers of the critical enzyme and target for intervention, Ghosh said.

Tang discovered a key enzyme called memapsin 2, or beta-secretase, that is involved in the development of Alzheimer's disease. The action of this enzyme on a special protein, called the amyloid precursor protein, leads to the formation of plaques in the brain. The development of an inhibitor compound targeting memapsin 2 could block this reaction, thus preventing the disease. Utilizing Tang's information about the enzyme, Ghosh designed the first memapsin 2 inhibitor.