Characterization of the adsorption process analogouspeptides on alumina gel

Abstract

Peptide antigen adsorption on aluminumhydroxide gel must be characterizedwhen formulating vaccines. In this worka peptide belonging to the amino-terminalregion of Plasmodium falciparum MerozoiteSurface Protein and its analogueshave been characterized. The adsorptionof 17 analogues on aluminum hydroxidewhich had greater than 10 mmol/L solubilitywas quantified at 298 K. Adsorptioncapacity and affinity constant parameterswere calculated by applying theLangmuir's adsorption model.The results have been presented inthree groups according to adsorption isothermtrajectory. The first group consistsof analogues where the first organizationof peptide molecules was presented atlow concentrations, followed by a rapidincrease in adsorption to high concentrations.The second group consists ofanalogues having an adsorption patternshowing the formation of a first layer atlow peptide concentrations and a secondlayer at greater concentrations. The thirdgroup contains analogues whose adsorptioninvolved the formation of two simplelayers, this being differentiated fromthe second group in that after the secondlayer had been completed, the amountadsorbed grew notably with increasedconcentration.The results revealed a more complexpattern that monolayer or bilayer formation.This work constitutes the firstapproach towards establishing an adsorbedlayer structure model using a peptidesystem.