Protein Origami: Modeling secondary structure hydrogen bonding by paper folding

Before Jmol, Chime, and Rasmol, molecular structure “viewers” consisted of carefully‐made physical models. The pioneers in the field of structural biology turned to stick or ball/stick models made of wood and metal ‐ such as the one preserved in the now‐iconic photo of James Watson and Francis Crick pointing to their 1953 DNA double helix. From wood balls and metal wires to modern plastic snap‐together systems, molecular models have a literal hands‐on appeal that a computer monitor and mouse do not. Even lower tech than computer or ball‐and‐stick models is simply folding paper. Origami‐style protein folding is instructive, accessible, and very cheap. An attempted re‐creation of an experiment in on‐paper protein folding recounted by Linus Pauling, led to development of an active learning exercise allowing students to discern how alignment of peptide backbone hydrogen bonds leads to formation of protein helical and sheet secondary structures. The materials and exercises used will be presented, along with assessment results of their impact on learning.