title: Limited conformational change of beta-lactoglobulin when adsorbed at the air-water interface.
abstract: Detailed insight can be obtained from proteins at and near the air-water interface using external reflection IR and circular dichroism techniques. Besides information on local protein concentrations and surface layer thickness, it is shown that beta-lactoglobulin displays a limited unfolding at the interface. The conformational change is comparable to that observed upon heat-induced aggregation of the protein and can be understood in view of the high surface concentration of the protein (approximately 40% volume fraction). The layer thickness and the conformational properties of the protein do not depend on the bulk concentration. After adsorption of beta-lactoglobulin to a preformed lipid monomolecular layer a similar conformational change is induced, suggesting that the folding properties of the protein itself determine the extent of conformational changes at the interfaces.
authors.affiliation: Wageningen Centre for Food Sciences, Diedenweg 20, Wageningen, The Netherlands. m.b.j.meinders@ato.wag-ur.nl
authors.forename: Marcel B J
authors.initials: MB
authors.lastname: Meinders
authors.forename: Harmen H J
authors.initials: HH
authors.lastname: De Jongh
mesh_terms: D000327:Adsorption; D000388:Air; D002942:Circular Dichroism; D007782:Lactoglobulins / Q000737:chemistry*; D011487:Protein Conformation; D013055:Spectrophotometry, Infrared; D014867:Water / Q000737:chemistry
chemical_list: D007782:Lactoglobulins; D014867:Water