Solid-state NMR investigation on the interactions between a synthetic montmorillonite and two homopolypeptides

Interactions of two homopolypeptides (polylysine and polyglutamic acid) with a synthetic montmorillonite were studied by H-1 MAS, H-1-Al-27 HETCOR and H-1-C-13 CP-MAS NMR experiments. H-1-Al-27 HETCOR with H-1 spin-diffusion NMR appears to be a powerful probe for the identification of the polypeptide fragments, which interact with the montmorillonite interlayer surfaces. In particular, selective interactions were observed between the polypepticle side-chains and the montmorillonite octahedral aluminum atoms.H-1-C-13 CP-MAS NMR experiments were used to assess the dynamics of the two polypeptides through the measurement of the t(1/2) characteristic time of selected carbons. Results indicate that the local mobility of the side chains and their interaction with the montmorillonite layers depend on the nature of the adsorbed polypeptides. (c) 2005 Elsevier Inc. All rights reserved.