title: Strong improvement of interfacial properties can result from slight structural modifications of proteins: the case of native and dry-heated lysozyme.
abstract: Identification of the key physicochemical parameters of proteins that determine their interfacial properties is still incomplete and represents a real stake challenge, especially for food proteins. Many studies have thus consisted in comparing the interfacial behavior of different proteins, but it is difficult to draw clear conclusions when the molecules are completely different on several levels. Here the adsorption process of a model protein, the hen egg-white lysozyme, and the same protein that underwent a thermal treatment in the dry state, was characterized. The consequences of this treatment have been previously studied: net charge and hydrophobicity increase and lesser protein stability, but no secondary and tertiary structure modification (Desfougères, Y.; Jardin, J.; Lechevalier, V.; Pezennec, S.; Nau, F. Biomacromolecules 2011, 12, 156-166). The present study shows that these slight modifications dramatically increase the interfacial properties of the protein, since the adsorption to the air-water interface is much faster and more efficient (higher surface pressure). Moreover, a thick and strongly viscoelastic multilayer film is created, while native lysozyme adsorbs in a fragile monolayer film. Another striking result is that completely different behaviors were observed between two molecular species, i.e., native and native-like lysozyme, even though these species could not be distinguished by usual spectroscopic methods. This suggests that the air-water interface could be considered as a useful tool to reveal very subtle differences between protein molecules.
authors: Agrocampus Ouest, UMR1253 STLO, F-35042 Rennes, France.
authors: Yann
authors: Y
authors: Desfougères
authors: Arnaud
authors: A
authors: Saint-Jalmes
authors: Anniina
authors: A
authors: Salonen
authors: Véronique
authors: V
authors: Vié
authors: Sylvie
authors: S
authors: Beaufils
authors: Stéphane
authors: S
authors: Pezennec
authors: Bernard
authors: B
authors: Desbat
authors: Valérie
authors: V
authors: Lechevalier
authors: Françoise
authors: F
authors: Nau
mesh_terms: D000327:Adsorption; D000388:Air; D000818:Animals; D002627:Chemistry, Physical; D002645:Chickens; D003890:Desiccation; D004548:Elasticity; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D018625:Microscopy, Atomic Force; D008968:Molecular Conformation; D009113:Muramidase / Q000032:analysis / Q000737:chemistry*; D011312:Pressure; D012212:Rheology; D013057:Spectrum Analysis; D055672:Static Electricity; D013499:Surface Properties; D013816:Thermodynamics; D014783:Viscosity; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; C421864:hen egg lysozyme; D009113:Muramidase