- Person
- Konrad Bloch
- Lived
- 1912–2000
- Field
- Biochemistry
- From
- German-American
The story
Konrad Bloch was born in 1912 in Neisse, Upper Silesia, into a Jewish family. He was studying chemistry in Munich when, in 1934, his studies were ended for racial reasons under the Nazi regime. After a period in Switzerland he emigrated to the United States in 1936 and earned a doctorate in biochemistry at Columbia University in 1938.
At Columbia he joined Rudolf Schoenheimer and David Rittenberg, pioneers of labelling molecules with isotopes so that their atoms could be tracked inside living things. In 1942 Bloch and Rittenberg began studying how the body makes cholesterol, the waxy molecule that is vital to cell membranes and hormones but which, in excess in the blood, clogs arteries. Most of the cholesterol in our blood is made by the liver, not eaten.
Bloch and Rittenberg showed that the building block is acetate, a simple two-carbon unit. At the University of Chicago, Bloch’s group used labelled acetate in bread mould and rats to trace every one of cholesterol’s carbon atoms back to acetate. He and others then worked out the route: acetate becomes mevalonic acid, which becomes isoprene-like five-carbon units, which join into squalene, which folds into lanosterol and is finally trimmed to cholesterol. Feodor Lynen in Munich independently solved key steps, and the two shared the 1964 Nobel Prize in Physiology or Medicine. Bloch also showed that bile acids and steroid hormones are made from cholesterol.
Bloch’s map revealed where to intervene. The rate-limiting step of the pathway is the conversion of HMG-CoA to mevalonate by the enzyme HMG-CoA reductase. Drugs that block this enzyme, the statins, were developed from the 1970s onward and cut the liver’s cholesterol production. Bloch did not invent statins, but his work on the pathway made it possible to know where to aim them. He spent his later career at Harvard and died in 2000.
Why it matters
Statins, which block a key step in the cholesterol pathway Bloch helped map, are taken by millions of people to lower cholesterol and prevent heart attacks and strokes.
About Konrad Bloch
Biochemist who fled Nazi Germany and mapped how the body builds cholesterol from acetate, the pathway whose key step statin drugs now block to protect millions of hearts. Nobel Prize 1964.
Sources
- Konrad Bloch, Biographical NobelPrize.org
- Konrad Bloch Wikipedia
- Chemistry Matters: Statin Drugs OpenStax Organic Chemistry
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.