Extreme stability in de novo-designed repeat arrays is determined by unusually stable short-range interactions.

ABSTRACT: Designed helical repeats (DHRs) are modular helix-loop-helix-loop protein structures that are tandemly repeated to form a superhelical array. Structures combining tandem DHRs demonstrate a wide range of molecular geometries, many of which are not observed in nature. Understanding cooperativity of DHR proteins provides insight into the molecular origins of Rosetta-based protein design hyperstability and facilitates comparison of energy distributions in artificial and naturally occurring protein folds. Here, we use a nearest-neighbor Ising model to quantify the intrinsic and interfacial free energies of four different DHRs. We measure the folding free energies of constructs with varying numbers of internal and terminal capping repeats for four different DHR folds, using guanidine-HCl and gly

SUBMITTER: Geiger-Schuller K 

PROVIDER: S-EPMC6055163 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature