Abstract
We recently demonstrated that the conger eel galectins, Congerin I and II, have evolved under significant selective pressure, with the emergence of a new strand-swap structure between subunits in Congerin I. To understand the structure-thermostability relationship of Congerins, and seek clues to the mechanism of their evolution, we improved the thermostability of Congerin II by rational design and in vitro evolutionary protein engineering. A resulting Tyr16/Thr88 double mutant exhibited structural features and thermostability similar to the naturally thermostable isoform, Congerin I. Thus, under artificial selective pressure, Congerin II partially reproduced the natural evolution of Congerin I.
