Conjugation of Preformed Polypeptides and Polymers

Proteins and peptide can be cmijugated with end-group reactive polymers. There are several methods and reactive groups suitable for this purpose, as pointed out in recent reviews [92, 94, 112]. Therefore, we will focus here on systems in which homopolypeptides prepared by NCA polymerization are conjugated with polymers. 

The PBLG-6-PDMAEMA copolymers also have been used to prepare micelles containing ultrasmaU supra-paramagnetic iron oxide nanoparticles. The micelles are formed by nanoparticle-induced transition from bilayers to micelles [117]. This approach - the synthesis of preformed polymer blocks and their combination by click chemistry - can also be transferred to two polypeptide blocks. PBLG and poly (trifluoracetyl-L lysine) (PTFALL) both can be synthesized by NCA polymerization with the aforementioned propargylamine or l-azido-3-aminopropane to give azide-or alkyne-terminated polypeptide blocks, which can subsequently be combined 

An AB2 Y-shaped polypeptide copolymer was synthesized by click chemistry. A-aminoethyl-3,5-(bisprogargyloxy)benzamide was used as initiator for A-benzyloxycarbonyl-L-lysine (ZLL)-NCA and 3-azido propylamine for BLG-NCA [121]. After deprotection, the block copolymer forms micelles in water with a PLL core at pH = 12 and with a PGA core at pH = 2. 

Zhou et al. prepared a rod-rod block copolymer by click chemistry. Again, 3-azidopropylamine was used as initiator to prepare azido end-functionalized PBLG (Fig. 17). Using an alkyne-functionalized ATRP initiator, an acrylate with a bulky mesogenic side was polymerized. The block copolymers show interesting solid state properties and exhibit liquid crystalline behavior above 135°C [122]. 

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