Homogeneous graft copolymerization and characterization of novel artificial glycoprotein: Chitosan‐poly(L‐tryptophan) copolymers with secondary structural side chains

Abstract

A novel series of artificial glycoprotein, peptide‐chitosan copolymers with secondary structural side chain have been synthesized by ring‐opening polymerization of L‐tryptophan N‐carboxyanhydride under homogeneous conditions. Their chemical structures and polymerization degree (DP) were characterized by IR, 13C NMR, and XRD spectra. Distinctly secondary protein structure has been found in the poly‐L‐tryptophan side chains of copolymers and with the lengthening of side chain (i.e., the increase of DP at the same time), its conformations could transfer from β‐sheet to α‐helix. The content of α‐helix reaches about 41% when DP of polytryptophan is 22. The solubility of graft copolymers in polar solvent strongly depends on the length of poly‐L‐tryptophan side chains. Unique fluorescence emission at 360 nm has been observed in the glycopolymers and the intensity shows the positive‐correlation with the increasing of DP of polytryptophan. Importantly, the fluorescence effect can be quenched easily by the coordination with copper ions which provides the possibility on the biosensor design. In comparison with chitosan, glycopolymers also present impressively enhanced compressive strength and elastic modules when it is blended with epoxy E 44 to form epoxy‐copolymer hybrid resin. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 925–934, 2009

Strategies to Fabricate Polypeptide-Based Structures via Ring-Opening Polymerization of N-Carboxyanhydrides

“…In addition to the non-linear star-shaped polypeptides, other grafted and highly branched polypeptide structures have been also reported. For the preparation of branched grafted polypeptides, the traditionally reported strategies “grafting onto” [ 211 , 212 , 213 , 214 , 215 ], “grafting from” [ 216 , 217 , 218 ] and “grafting through” [ 219 , 220 ] methodology have been employed.…”

A low-toxic artificial fluorescent glycoprotein can serve as an efficient cytoplasmic labeling in living cell

“…here a strategy for designing a new fluorescent compound as a specific cytoplasmic labeling material with low-toxicity, by employing low molecular weight (M W ) chitosan as a scaffold and poly-l-cysteine as side chains, to form a well-defined fluorescent glycoprotein (chitosan-poly-l-cysteine, CPC) (Xiang, Si, Zhang, Liu, & Guo, 2009). Here, thiol groups on the side chains were used as the important chromophores besides pyranose rings of chitosan scaffold.…”

Synthesis, Characterization, and Performance of a Novel Polymeric Cationic Surfactant Based on Low Molecular Weight Chitosan and 3‐Chloro‐2‐Hydroxypropyl Dimethyl Dehydroabietyl Ammonium Chloride (CHPDMDHA)

“…Therefore, the degradation of CTS and the preparation of low molecular weight chitosan (LWCS) have received increasing interest over the last decade [11][12][13]. Meanwhile, numerous applications of LWCS in various fields have been reported in the literature [14][15][16][17][18][19][20][21], especially in the preparation of polymeric surfactants [22][23][24][25][26][27][28][29].…”