Effect of Solvent Composition on the Adsorption of Diblock Polypeptides on Polystyrene Latex

Abstract

Peptides with one hydrophilic and one non-polar block or with both hydrophilic blocks with opposite charges were chemically synthesized and their adsorption behavior on polystyrene latex studied. Adsorption experiments were performed at different pHs and in mixtures of water/methanol and water glycerol. the thickness of the adsorbed layer was determined by dynamic light scattering (DLS). Positively charged blocks show high affinity for the surface whereas negatively charged blocks were excluded from it. Poly(Lys) has the highest affinity by the surface while (Glu)14-b-(Ala)5 has the lowest. Adsorption of all peptides was inhibited by methanol and promoted by glycerol whereas the presence of cosolvents affected the adsorbed layer thickness of some peptides ((Lys)30-b-(Ala)41) but not others ((Lys)5-b-(Glu)6). the behavior of (Lys)5-b-(Glu)6 is somehow intriguing. This peptide forms aggregates with the latex at pH > 8 but the aggregates dissolve as the pH is increased above 9 and the process is completely reversible. the association of latex escapes a simple explanation.

Department(s)

Chemical and Biochemical Engineering

Keywords and Phrases

Adsorption; Dynamic light scattering; Peptide

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Interamerican Congress of Chemical Engneering, All rights reserved.

Publication Date

01 Jan 2006

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