Wednesday, December 20, 2006
Nobel Laureates: Hans Krebs
The Nobel Prize in Medicine 1953.
"for his discovery of the citric acid cycle"
Hans Krebs (1900-1981) received the Nobel Prize for working out the pathway for oxidation of the two carbon acetyl group on acetyl-CoA via a series of tricarboxylic intermediates. The cyclic pathway is now known as the Krebs cycle, the citric acid cycle, or the tricarboxylic acid cycle (TCA cycle).
Krebs had previously been known for his excellent work on the urea cycle in the 1920's and 30's. However, the citric acid cycle was controversial from the beginning. (See Monday's Molecule #6.) By the time he received the Nobel Prize, most biochemists were convinced but there were some hold-outs, making this one of the more controversial awards.
The modern citric acid cycle differs very little from the one published by Krebs over fifty years ago. The main difference is that today we recognize cis-aconitate as an intermediate in the reaction catalyzed by aconitase and not as a separate intermediate in the pathway.