for National Geographic News
What are proteins? How are they structured? What's the difference between a protein in a human and the same protein in a lizard? Ask Mary Anne Clark these questions and she is likely to respond with an earful of music.
Clark is a biologist at Texas Wesleyan University in Fort Worth, and she's part of a growing field of science educators who use so-called protein music to help illustrate the basic structure of the building blocks of life.
- Dog DNA Study Yields Clues to Origins of Breeds
- Prehistoric DNA to Help Solve Human-Evolution Mysteries?
- Human, Dog Genomes Similar, Study Finds
- Ancient Bear DNA MappedA 1st for Extinct Species
- Scientists Recreate Genome of Ancient Human Ancestor
- Chimps, Humans 96 Percent the Same, Gene Study Finds
All living things are made up of proteins. Each protein is a string of amino acids. There are 20 different amino acids, and each protein can consist of dozens to thousands of them.
Scientists write down these amino acid sequences as series of text letters. Clark and her colleagues assign musical notes to the different values of the amino acids in each sequence. The result is music in the form of "protein songs."
By listening to the songs, scientists and students alike can hear the structure of a protein. And when the songs of the same protein from different species are played together, their similarities and differences are apparent to the ear.
"It's an illustration transferred into a medium people will find more accessible than just [text] sequences," Clark said. "If you look at protein sequences, if you just read those as they are written down, recorded in a database, it's hard to get a sense for the pattern."
When people look at a page full of text corresponding to protein sequences, Clark explained, they tend spot clusters of letters but fail to see the larger pattern.
"If you play [the protein song for that sequence] you get that sense of the pattern much more strongly," she said. "That's my feeling at least. You hear stuff you can't see."
One song for a protein may sound different than another for the same protein, depending on how notes are assigned to amino acids' various properties. For example, Clark tends to arrange her compositions based on the protein's solubility.
"Where it's soluble and insoluble is one of the big factors in determining how [the protein] folds up," she said. Solubility influences how proteins fold, and those folds determine what category a certain protein belongs to.
In 1996 Ross King, a computer scientist at the University of Wales, Aberystwyth, wrote a program called Protein Music. It assigns a note to each of the three compounds that make up amino acids and a note to various amino acid propertiescharge, solubility, and so on.
SOURCES AND RELATED WEB SITES