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of the human genome, they are already moving on to the next challenge - unraveling the secret of protein, the basic building block of life.
Proteins are produced by the body's genes, and researchers want to find out why they grow and develop in a certain way, folding into predetermined shapes according to their various functions in the body.
Those various three-dimensional forms of proteins, from barrel to spherical to doughnut shapes, are significant in determining their biological function in the body. A better understanding of how this process works is the key to unlocking a treasure trove of medical knowledge. Proteins do all the heavy lifting essential to life, keeping the human body healthy by maintaining all the major systems from the immune to the nervous system.
"Thus defective proteins, created by faulty genes, can wreak havoc," said Steve Scherer, a scientist at the Human Genome Sequencing Center, Baylor College of Medicine, in Houston, Texas.
Like building blocks, proteins are designed to fit together, and misshapen ones will fail to do so. "A defect in a gene can cause a defect in a protein," he said. "It can have an effect on the folding (of the protein) itself or on the active site (where proteins join). If the active site pocket is destroyed, the two proteins which might need to fit together like a lock and key cannot do so."
A defective protein can cause diseases like cystic fibrosis and sickle cell anemia. So rather than seek to replace the gene, some scientists see the solution in replacing the protein or in some cases in changing the behavior of the protein.
Later this year the National Institutes of Health (NIH) near Washington will launch a program involving nine other countries and costing $20 million. The goal is to catalogue the characteristic folds of every family of protein using X-ray crystallography or nuclear magnetic resonance.
"What we are interested in doing, in the course of 10 years, is determining the structures of between 5,000 to 10,000 representative folds of proteins," said Charles Edmonds, program director of cell biology and biophysics at NIH.
Celera Genomics, which along with the Human Genome Project announced that it had sequenced the billions of chemical components that make up the human genome, is also working on the sequencing of proteins.
As is IBM, better known as the computer leader, which is also delving deep into protein research. It intends to build by 2004 the world's most powerful computer, Blue Gene, capable of carrying out a dizzying 1,000 trillion operations a second.
The goal of all that number crunching is to create a model of the movements of the tens of thousands of atoms inside a protein as it begins to fold, an operation that would take 300 years to complete with current computing power.
Blue Gene will do it in a year, said Sharon Nunes, director of emerging technologies at IBM. "When you understand what the proteins does in the body, that is when you can make significant advances in trying to understand and prevent a disease," she said. "By understanding the mechanism of how a protein folds ... we can help drug companies to fundamentally understand how to design drugs"
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