Corrigendum to “Electrochemical characterization of globotriose-containing self-assembled monolayers on nanoporous gold and their binding of soybean agglutinin”

The interaction of the glycoalkaloid tomatine with monolayers of a phospholipid (dimyristoylphosphatidyl-choline, DMPC), and sphingolipid (egg sphingomyelin), and cholesterol is compared. Using measurements ofthe surface pressure response as a function of the subphase concentration of tomatine, interfacial bindingconstants areestimated for mixed monolayers of DMPC and cholesterol and for those of egg sphingomyelin andcholesterol of mole ratio 7:3. The binding constants obtained suggest a stronger interaction of tomatine withDMPC and cholesterol mixed monolayers, reflecting easier displacement of cholesterol from its interactionwith DMPC than from its interaction with egg sphingomyelin. Mixtures of tomatine and cholesterol are foundto spread directly at the water–air interface and form stable monolayers, suggesting that cholesterol holdstomatine at the interface despite the absence of observed monolayer behavior for tomatine alone. Theinteraction of tomatine with DMPC and cholesterol monolayers is found to exhibit a pH dependence inagreement with previously reported results for its interaction with liposomes; in particular, the interaction ismuch less at pH 5 than at pH 7 or pH 9. It is found that while tomatine interacts strongly with monolayerscontaining sitosterol, it does not interact with monolayers containing sitosterol glucoside. The response ofmonolayers of varying composition of DMPC and cholesterol to tomatine is also examined. Brewster anglemicroscopy (BAM) reveals further evidence for formation of suspected islands of tomatine+cholesterolcomplexes upon interaction with mixed monolayers of lipid and sterol.