How it began
Luis F. Leloir, born in Paris to Argentine parents and raised in Buenos Aires, directed the Instituto de Investigaciones Bioquimicas of the Fundacion Campomar. With his early collaborators Ranwel Caputto, Carlos E. Cardini, Raul Trucco and Alejandro C. Paladini he began work on the metabolism of galactose. That work led to the isolation of glucose 1,6-diphosphate and uridine diphosphate glucose. The Nobel Foundation dates the key discovery to 1949.
How it works
A sugar nucleotide is a molecule made of a nucleotide, the kind of unit that also builds DNA, joined to a sugar. Leloir found that the conversion of one type of sugar into another depends on such a molecule. Uridine diphosphate glucose was then shown to act as a glucose donor, handing its sugar to a growing molecule. In this way cells assemble larger carbohydrates from simple sugars.
What changed first
After the first compound was isolated, the Buenos Aires group showed that uridine diphosphate glucose donates glucose in the synthesis of trehalose, with Enrico Cabib in 1953, and of sucrose, with Cardini and J. Chiriboga in 1955. Other sugar nucleotides, including uridine diphosphate acetylglucosamine and guanosine diphosphate mannose, were also isolated in the same laboratory.
What lasted
Further work showed that uridine diphosphate glucose is involved in the synthesis of glycogen and adenosine diphosphate glucose in that of starch. In 1970 Leloir received the Nobel Prize in Chemistry for his discovery of sugar nucleotides and their role in the biosynthesis of carbohydrates. A review marking the fiftieth anniversary of the prize traced current research on nucleotide sugar metabolism in plants back to his work.
