Proteins, long strings of amino acids, spontaneously fold into intricate shapes that enable them to perform a cell’s dazzling variety of functions. To better understand the forces that determine these shapes, scientists have developed a technique for stretching a protein to follow in reverse the path it took when folding.
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“The basic idea is to pull the molecule at both ends to stretch it and see what happens,” says Ching-Hwa Kiang, a biological physicist at Rice University in Houston.