Journal Article

Cooperative polymerization of α-helices induced by macromolecular architecture

Baumgartner, Ryan, Song, Ziyuan, Cheng, Jianjun, Lin, Yao, Fu, Hailin

2017

Overview

Catalysis observed in enzymatic processes and protein polymerizations often relies on the use of supramolecular interactions and the organization of functional elements in order to gain control over the spatial and temporal elements of fundamental cellular processes. Harnessing these cooperative interactions to catalyse reactions in synthetic systems, however, remains challenging due to the difficulty in creating structurally controlled macromolecules. Here, we report a polypeptide-based macromolecule with spatially organized α-helices that can catalyse its own formation. The system consists of a linear polymeric scaffold containing a high density of initiating groups from which polypeptides are grown, forming a brush polymer. The folding of polypeptide side chains into α-helices dramatically enhances the polymerization rate due to cooperative interactions of macrodipoles between neighbouring α-helices. The parameters that affect the rate are elucidated by a two-stage kinetic model using principles from nucleation-controlled protein polymerizations; the key difference being the irreversible nature of this polymerization. The secondary and tertiary structure of a protein has profound implications on function and catalysis. Now, both the secondary and tertiary structures of a synthetic polymer have been utilized to catalyse the polymerization of N-carboxyanhydrides. Both the folding of the resulting polypeptides into α-helices and their macromolecular organization dramatically enhance the polymerization rate.

• Publisher: Nature Publishing Group UK
• Subject: 147/3 / 639/638/455/941 / 639/638/455/953 / 639/638/455/959 / 639/638/77/603 / Analytical Chemistry / Biochemistry / Chemistry / Chemistry/Food Science / Inorganic Chemistry / Organic Chemistry / Physical Chemistry