We use a molecular evolution strategy called in vitro selection to identify new proteins and peptides with novel structural and functional properties. We present a variant of a de novo evolved ATP binding protein that has been selected for greater folding stability in the presence of chemical denaturants. We present biophysical characterization of this novel protein. Additionally, we present evidence of serendipitous enzymatic activity present in this protein variant. The presence of unselected for enzymatic activity in what was selected as a binding protein presents supporting evidence for a “binding first” model of enzyme evolution.