Amino polymers complex formation

Ferruti, P. and Barbucci, R. Linear Amino Polymers Synthesis, Protonation and Complex Formation. Vol. 58, pp. 59—92. 

It is well known that PLL can assume an a-helical conformation above pH 10. The complex formation between PLL and heme was carried out at pH 12, where the e-amino groups of the side chain of PLL were not protonated and PLL formed a complete a-helix14. The helix parameter (molar dlipticity at 222 nm) was the same before and after complex formation with heme. The helix content, Le. the overall conformation of PLL, was not affected. The viscosity of the PLL solution also remained constant on the addition of ferriheme14. These results mean that complex formation occurs with a structure complementary to the a-helical conformation and that bending of the PLL helix does not occur. The inter-polymer sandwich structure proposed by Blauer [Fig. 4(c)]9 is thus ruled out. The structure... 

The binding by the charge transfer complex formation is observed in polymerizations of p-nitrophenylphenylalanine NCA and some p-nitrophenyl derivatives of a-amino acid NCA by the nucleophile-containing polymer catalysts (103). Results are shown in Table 9. 

Linear amino polymers containing basic nitrogen atoms are critically reviewed with regard to their synthesis, protonation and complex formation in solution with metal ions. Cross linked resins having essentially the same structure as linear polymers, are also mentioned. As far as the proto-nation is concerned, special care has been given to thermodynamic aspects, and to the most probable protonation mechanism. Complexing abilities of these polymers have been evaluated through stability constants and spectroscopic parameters. Practical implications of the properties have been considered. 

Linear Amino Polymers — Synthesis, Protonation and Complex Formation... 

The formation of the polymer complex was observed between poly-VAd and natural RNA. In order to get better information about the specific interaction between poly-VAd and RNA, further studies on the interaction of N-methyl and N,N-dimethyl derivatives of poly-VAd with RNA were carried out. It was found that mono- or dimethylation of the 6-amino group of poly-VAd depresses the specific polymer-polymer interaction, and no polymer complex was formed between the N,N-dimethyl derivative of poly-VAd and RNA. This fact suggests that the interaction between poly-VAd and RNA was caused by hydrogen bonding between the complementary nucleic add bases. 

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