Member Nancy asked us to clarify our newsletter about Linus Pauling’s contribution to the discovery of the alpha-helix structure of DNA. It’s well known that Watson, Crick, and Wilkins were the scientists that finally modeled the structure of DNA correctly and discovered that DNA contains genes – earning them the Nobel Prize in Physiology and Medicine in 1962. So what did Pauling discover about “the nature of chemical bonds” to earn himself a Nobel Prize? Turns out, that’s quite a story.
Pauling, Crick, Watson, and many other top scientists competed for decades to be the first to discover the location of human genes. As stated in the Oregon State University Archives video we shared, the chemical bonds he was primarily researching were proteins which he, and many other top scientists, believed to contain genes.Schrodinger narrowed down the location of genes to chromosomes in a paper published in 1933. The two major molecular structures within chromosomes thought to contain genes were proteins and nucleic acids (DNA). An under-appreciated paper published in 1944 by William Avery postulated that genes were stored in DNA, but Pauling and many other top scientists dismissed it, favoring proteins.
Pauling was the first to publish detailed models of protein structures in a series of papers in 1951. During this research, he contracted a cold, which left him bedridden for a few days. In the video he jokes, “This was before the vitamin C days.” During his downtime, he mapped out the alpha helix structure of DNA, but he didn’t have a good x-ray of DNA, which led to one bond angle of an alpha carbon atom having an inaccurate value. That’s right, his model was off by only 1 spec. Of course, was only working at it part-time and without an x-ray to guide him. His research, however, ultimately led to his Nobel Prize in 1954.
Watson and Crick applied Pauling’s strategy for mapping proteins to their research on DNA, using the high-quality x-rays by Wilkins (who refused to let Pauling see them, as they were rivals), and the famous pair of researchers discovered that genes are actually stored in DNA rather than proteins. Watson, Crick, and Wilkins shared the Nobel Prize for these findings.
In the scientific community, Pauling had been favored to make this discovery, so it was quite an upset for Watson, Crick, and Wilkins to win the day. But Pauling just loved to work, laughed off the loss, and moved on to his research on sickle cell anemia and vitamin C.
Further reading:
OSU Archives: The Race for DNA
http://scarc.library.
http://www.nobelprize.org/
http://www.nobelprize.org/