HMGA1a protein unfolds or refolds synthetic DNA-chromophore hybrid polymers: a chaperone-like behavior.

High group mobility protein, HMGA1a, was found to play a chaperone-like role in the folding or unfolding of hybrid polymers that contained well-defined synthetic chromophores and DNA sequences. The synthetic and biological hybrid polymers folded into hydrophobic chromophoric nanostructures in water, but existed as partially unfolded configurations in pH or salt buffers. The presence of HMGA1a induced unfolding of the hybrid DNA-chromophore polymer in pure water, whereas the protein promoted refolding of the same polymer in various pH or salt buffers. The origin of the chaperone-like properties probably comes from the ability of HMGA1a to reversibly bind both synthetic chromophores and single stranded DNA. The unfolding mechanisms and the binding stoichiometry of protein-hybrid polymers depended on the sequence of the synthetic polymers.