Visionary Appreciation

Ribonuclease enzymes cut RNA, the molecule that translates DNA into proteins; ribonuclease history links Swarthmore’s first Nobel laureate, Christian Anfinsen ’37, H’65, with Lisa Steiner ’54. The former received the Nobel Prize for Chemistry in 1972 with two colleagues for showing that ribonuclease’s folding into a functional form was directed by its amino acid sequence and ultimately by its DNA.

Curiously, key experiments that earned Anfinsen the Nobel Prize were independently done by Steiner as a medical student at Yale, but never published, an unfortunate twist of fate outlined in a June 2018 essay published in Cell (bit.ly/LSteiner).

In her thesis, Steiner showed that the enzyme ribonuclease lost activity when its disulfide bridges were reduced, but that much of its activity was restored when the bridges were allowed to reform. Reading of research that would later lead to Anfinsen’s shared Nobel Prize, Steiner’s department chair’s only comment was to correct her spelling of ‘‘thioglycolic acid.’’

Steiner, who became the first female faculty member in MIT’s biology department, did not hold a grudge—in the 1960s, she read Anfinsen’s newly published papers on ribonuclease and was delighted that his work confirmed her earlier studies.

The story came to wider light in 1995, soon after Anfinsen’s death, following a chance conversation among scientists editing a review series. Renowned protein chemist John Edsall concluded that Steiner’s work was not recognized because it was completed too soon, before the major steps in protein synthesis were fully elucidated. The structural question Anfinsen answered had not yet been asked when Steiner was doing her experiments.

This Oct. 15, the National Institutes of Health held a special symposium to honor Anfinsen’s life and work; fittingly, they asked Steiner to participate, and she graciously agreed.