In the early 1930s, when Linus Pauling first became involved in the study of biomolecules,
very little was known about "the mysterious protoplasm." Today, we live in an era
of molecular biology, with all its attendant benefits: Improved medical care, higher
crop yields, new processes, new products, and new industries.
Pauling played an important part in several fields. He made important advances in
immunology. He discovered the first "molecular disease" in a protein molecule and
linked it firmly to a genetic basis. He found a way to cut through conflicting data
and present detailed atomic maps of likely protein structures years before anyone
else thought it would be possible. Sections of his alpha helix and pleated sheet structures
have been found in the majority of living proteins. He is justly considered one of
the founding fathers of molecular biology.
At the same time, Pauling's personal charisma, persuasive speaking abilities, powerful
teaching skills, and publicity seeking have led some observers to overemphasize his
contributions at the expense of others. The discovery of the alpha helix, in particular,
has achieved the status of legend (helped by Pauling's own story-telling about his
time in England). While an important advance, the alpha helix (and pleated sheet)
should be recognized for what they are: secondary structures that explain little about
the functioning of active proteins. As science historian Joseph Fruton wrote in 1999,
"Although the alpha helix turned out to be a prominent feature of the structure of
myoglobin, as more crystalline proteins were examined in later years, many of them
exhibited much less helical content and some, like chymotrypsin, do not appear to
have appreciable alpha-helix content. The pleated-sheet structure has been identified
in parts of many proteins, but there are also stretches of the peptide chain in the
form of irregular loops and turns." Sections of the alpha helix can be distorted.
Sections of pleated sheet are often twisted.
In other words, proteins are far more complicated and varied than anyone, including
Still, he had a vital effect on the history of the field that went far beyond his
own contributions. Pauling's emphasis on the primacy of molecular structure; his flexible
approach to data interpretation; rejection of "magic number" theorizing; insistence
on playing the game by the rules of chemistry; and well-publicized successes all proved
critical in inspiring the sometimes more important research of those who followed.
Perhaps the most striking example is the work of Watson and Crick, who consciously
aped Pauling's methods in their successful attempt to find a structure for DNA.
Pauling was, in short, a pioneer. Every molecular biologist today owes a debt to his
insights, methods, and discoveries.