The discovery of a substance that zips itself together from simple protein building blocks may help scientists unravel the mystery of Alzheimer's disease. Biologist Shuguang Zhang at Massachusetts Institute of Technology was studying EAK16--a yeast protein constituent made of 16 amino acids--because pairs of the protein strings have the unusual habit of binding like the halves of a zipper. When Zhang exposed these zippers to a salt solution, they turned into a thin membrane resembling the brain-clogging plaque of Alzheimer's. Understanding why, says Zhang, may lead to ways to disrupt the formation of the plaque.
What's more, the membrane may have valuable properties. It starts out as a biopolymer that resists most chemical activity, but then gradually reverts back to its amino-acid building blocks. That leads Zhang to predict that it could coat drugs to protect them from stomach enzymes while allowing the medication to be absorbed by the intestines.