Regulating protein folding including assisting de novo folding, preventing misfolding and aggregation, and facilitating refolding of proteins are of significant importance for retaining protein's biological activities. Here, we report a mixed shell polymeric micelle (MSPM)-based self-cooperative nanochaperone (self-co-nChap) with enhanced activity to facilitate protein refolding. This self-co-nChap was fabricated by introducing Hsp40-mimetic artificial carriers into the traditional nanochaperone to cooperate with the Hsp70-mimetic confined hydrophobic microdomains. The artificial carrier facilitates transfer and immobilization of client proteins into confined hydrophobic microdomains, by which significantly improving self-co-nChap's capability to inhibit unfolding and aggregation of client proteins, and finally facilitating refolding. Compared to traditional nanochaperones, the self-co-nChap significantly enhances the thermal stability of horseradish peroxidase (HRP) epicyclically under harsher conditions. Moreover, the self-co-nChap efficiently protects misfolding-prone proteins, such as immunoglobulin G (IgG) antibody from thermal denaturation, which is hardly achieved using traditional nanochaperones. In addition, a kinetic partitioning mechanism was devised to explain how self-co-nChap facilitates refolding by regulating the cooperative effect of kinetics between the nanochaperone and client proteins. This work provides a novel strategy for the design of protein folding regulatory materials, including nanochaperones.

A self-cooperative nanochaperone mimics the cooperation of Hsp40 with Hsp70 was reported. The Hsp40-mimetic facilitates the transfer of client protein into the Hsp70-mimetic hydrophobic microdomain, significantly enhancing the chaperone activity.