Chemical Redirection of Protein Folding Landscapes via Lysine-Targeted Induction of Helix-to-Sheet Transitions

The spontaneous transition from α-helix to β-sheet in proteins is a transformative structural event essential for diverse biological functions, yet its dysregulation is a hallmark of protein misfolding diseases. Controlling this transition with molecular precision remains a significant challenge in chemical biology. Here, we report the development of lysine-targeted small hydrophobic chemical constructs (HCCs) designed to bypass native folding pathways and induce α-to-β structural remodeling across a spectrum of model proteins. Through a screening of four HCCs, we identified an activated N,N-dimethyl leucine derivative as a potent, dose-dependent inducer of this conformational switch. Using ion mobility-mass spectrometry and Fourier transform infrared spectroscopy, we demonstrate that these chemical modifications effectively recapitulate the transition from helical architectures to β-sheet-rich assemblies. Beyond structural remodeling, we show that this chemically induced transition drives significant functional shifts, including the precise modulation of cytochrome c catalytic activity and the regulation of amyloidogenic aggregation in lysozyme. Our findings establish HCCs as a versatile platform for interrogating protein conformational landscapes and provide a synthetic strategy to manipulate protein topology. This approach opens new avenues for protein engineering and offers deep insights into the fundamental principles governing protein homeostasis and the molecular basis of proteotoxicity.