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Updated: Feb 1, 2026

Capillary Electrophoresis to Monitor Peptide Grafting onto Chitosan Films in Real Time
Published on: October 26, 2016
About endothermic sorption of tyrosine on chitosan films
Eduardo A Takara1, Esteban G Vega-Hissi2, Juan C Garro-Martinez2
1Instituto de Física Aplicada INFAP-FQBF-UNSL-CONICET, Av. Ejército de los Andes 950, Bloque III, D5700HHW, San Luis, Argentina.
Abstract:
Sorption of l- and d-Tyrosine (Tyr) from aqueous solutions on chiral membranes of chitosan (CH) was studied. A high adsorption in the membrane, with a marked enantioselectivity to l-Tyr, was found. Computational calculations carried out by docking and molecular dynamics (MD) showed a difference in the affinity of the enantiomers and two regions of adsorption in the polymer matrix. The interactions of the enantiomers with the polymer matrix were studied by using FTIR, DRx, DSC and TG measurements. These results indicate that adsorption of Tyr reduces the crystallinity of the membrane and generates a rearrangement of the chains, decreasing the intercatenary spacing. Also, it was observed that the hydrated polymorph to anhydrous polymorph ratio has changed during adsorption, that is, water bound to chitosan is also modified. The energy balance of the system hydrogen bonding, desolvation and the conformational changes resulted in a spontaneous and endothermic process.
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