title: Denaturation resistance of beta-lactoglobulin in monomolecular films at the air-water interface.
abstract: Using X-ray reflectometry we report strong differences in the denaturation response of beta-lactoglobulin adsorbed as a monomolecular film at the air-water interface from that observed in mixed denaturant/beta-lactoglobulin bulk solutions. Using the "flow trough" technique an isolated monomolecular film of the protein showed little change in structure when subjected to a 4.0 M guanidinium hydrochloride substrate. Unlike the bulk solution where a new protein layer structure appears, small changes in the protein packing and the roughness of the film are the only evidence of change. These parameters have been studied as a function of denaturant concentration and film quality. The strength of the response depends on the degree of perfection of the originally formed film; quickly formed films are more easily denatured. As the response is so subtle, possible interfering effects such as denaturant release of protein adsorbed on the trough have been quantified.
authors.affiliation: Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia.
authors.forename: Jhih-Min
authors.initials: JM
authors.lastname: Lin
authors.forename: John W
authors.initials: JW
authors.lastname: White
mesh_terms: D000388:Air; D019791:Guanidine / Q000737:chemistry; D007782:Lactoglobulins / Q000737:chemistry*; D011489:Protein Denaturation; D014867:Water / Q000737:chemistry*
chemical_list: D007782:Lactoglobulins; D014867:Water; D019791:Guanidine