The DNA-encoded catalytic machinery of the cell can rapidly learn to promote new chemical reactions when we provide new reagents and the appropriate incentive in the form of artificial selection.
After returning from Cambridge in 1936, I did some work with J. M. Mioz on the oxidation of fatty acids in liver.
Ultimately, life is a chemical interaction.
It was obvious-to me at any rate-that the answer was to why an enzyme is able to speed up a chemical reaction by as much as 10 million times. It had to do this by lowering the energy of activation-the energy of forming the activated complex. It could do this by forming strong bonds with the activated complex, but only weak bonds with the reactants or products.
We managed to prepare a cell-free system which was active when suitably supplemented, and this was a novel result since the process of oxidation was believed to require the integrity of the cells.
In my first publishable research, I obtained evidence that the replication of polio viral RNA engendered a multi-stranded intermediate, although my description of that intermediate proved flawed in its details.
As is known, the sugar molecule as it passes through lactic acid can easily be split by purely chemical means.
Moreover the incorporation requires the same components needed for protein synthesis, and is inhibited by the same inhibitors. Thus the system is most unlikely to be a complete artefact and is very probably closely related to genuine protein synthesis.
As has repeatedly been stated, the underlying hypothesis, which in a number of cases has been supported by direct experimental evidence, is that each gene controls the production, function, and specificity of a particular enzyme.
My interest in protein breakdown as a research problem began in l955 at about the time I joined the Biochemistry Department of Yale University. It was known that proteins break down intracellularly in the mature animal.
We look at the human body as a biochemical machine controlled by genes and therefore we see a mechanical aspect to life and then try to understand the nature of mechanics by looking at how the physical parts interact with each other, so that's biochemistry.
Proteins aren't designed, they're evolved.
Isobutanol is not a natural product, but we evolved an enzyme that makes it possible to convert plant sugars to this precursor to jet fuel.
Life does depend on accurate replication of molecules, and its complexity often requires that an enzyme shall accept one molecular species or type and transform it to equally specific products.
We allowed ourselves to become particularly interested in research into the appearance of intermediate products of sugar decomposition during cell-free fermentation.
