Key to protein folding is discovered

KNOXVILLE, Tenn., Sept. 20 (UPI) -- A team of U.S. researchers has discovered a protein's interactions with water determine how it folds into a three-dimensional shape.

The team led by biophysicist Jeremy Smith of the University of Tennessee used U.S., Italian and German high-performance computers to study simulations of peptides -- the smaller chains of amino acids that make up proteins.

"Understanding the mechanism by which proteins fold up into unique three-dimensional architectures is a holy grail in molecular biology," said Smith, who also is affiliated with the Oak Ridge National Laboratory. He said a protein's function is determined by its shape, but that shape cannot be predicted by identifying the amino acids making up the protein.

The researchers demonstrated folding is determined largely by how areas of the protein interact with water. Areas that shun water are said to be hydrophobic, and the team found the way water wets such hydrophobic areas determines the ultimate shape and behavior of the peptide.

The team also discovered the length of the hydrophobic areas is critical to understanding how the protein folds.

The study appears in the Proceedings of the National Academy of Sciences.

Copyright 2007 by United Press International

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