Anfinsen's Ribonuclease Is Still the Best Demo in Biochemistry

Unfold an enzyme, take away the denaturant and watch it remember what it was.

By The Editors/October 31, 2026/1 min read

Christian Anfinsen unfolded ribonuclease A with urea and a reducing agent, then removed them by dialysis. The enzyme slowly refolded and regained its activity with no help from the cell.

The experiment fits in a paragraph. It also set the terms for the next half century of structural biology, because it implied that the information for a fold is already in the sequence.

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