The hormone that triggers red blood cell production, erythropoietin (EPO), is often given to patients undergoing treatment for kidney failure or cancer. A team at the Sloan-Kettering Institute for Cancer Research in New York city has devised a method to synthesize a pure form of this complex protein from scratch.

Samuel Danishefsky and his colleagues built the protein, which until now could be made only in cell culture, by piecing together four glycopeptides that they had assembled in the lab. The researchers then folded the amino-acid chain into the final protein and used mass spectroscopy to verify the structure. Umbilical-cord blood-progenitor cells that were cultured with the synthetic molecule formed red blood cells.

Angew. Chem. Int. Edn. https://doi.org/10.1002/anie.201206090 (2012)