Biological functions in livings occurs by interactions, which ultimately imply stereo- and chemical-complementarity between the binding partners. In protein interaction, definite protein segments, such as exposed loops, helix-loop-helix motifs, etc. are involved in the formation of complexes that ultimately trigger the physiological responses.
Here, as a mimic of protein interactors, we attempted the synthesis of molecularly imprinted nanogels (nanoMIPs), performed by means of the molecular imprinting technique  and in precipitation polymerization conditions , that were addressed at the recognition of a structured peptide: the loop-shaped 9mer peptide with sequence C1-(X)n=7-C9 and fixed by a disulphyde bond.
The nanoMIPs were about 50 nm in size and 2 106 Da of mean molecular weight. They exhibited high affinity (Kd = 9 10-9 M) and structural selectivity for the loop-shaped peptide. Additionally, it was observed that the nanoMIPs promoted a fast formation of the loop-shaped peptide, by the oxidation of the linear precursor peptide .
These results demonstrated the feasibility of the structural imprinting and hinted at a possible role of the nanoMIPs to assist the refolding of peptide segments into defined structures, anticipating polymeric nanomachines for counteracting folding defects.
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