February 21, 1911–December 25, 1995

BY FRANCES M. FINN AND BERT W. O’MALLEY

KLAUS HOFMANN WORKED in many areas of chemistry and biochemistry over his long and productive career. His published work covers the fields of steroids, enzymes, vitamins, fatty acids, and peptides. Without question, though, he was best known for his contributions to the field of peptides. His most publicized, though not the one he considered his most fundamental contribution, was the synthesis of a fully active, shortened chain of the pituitary hormone adrenocorticotropin (ACTH). His work on ACTH led to the recognition that peptide hormones, unlike steroid hormones, could be dramatically modified without substantially altering their biological potency. In his later work on peptides he was able to delineate the types of amino acids that contributed to the strong interactions between peptide chains that were vital to the strong and specific interactions responsible for recognition and binding of the hormone by its specific receptor.

Klaus Hofmann was born in Karlsruhe, Germany. His father died when he was only a year old and his mother returned with her son to Switzerland, where he was to remain until a Rockefeller Foundation Fellowship brought him to the United States in 1938 at the age of 27. Even as a