title: Effect of N-Ethylmaleimide as a Blocker of Disulfide Crosslinks Formation on the Alkali-Cold Gelation of Whey Proteins.
abstract: N-ethylmaleimide (NEM) was used to verify that no new disulfide crosslinks were formed during the fascinating rheology of the alkali cold-gelation of whey proteins, which show Sol-Gel-Sol transitions with time at pH > 11.5. These dynamic transitions involve the formation and subsequent destruction of non-covalent interactions between soluble whey aggregates. Therefore, incubation of aggregates with NEM was expected not to affect much the rheology. Experiments show that very little additions of NEM, such as 0.5 mol per mol of protein, delayed and significantly strengthened the metastable gels formed. Interactions between whey protein aggregates were surprisingly enhanced during incubation with NEM as inferred from oscillatory rheometry at different protein concentrations, dynamic swelling, Trp fluorescence and SDS-PAGE measurements.
authors.affiliation: Suzhou Key Laboratory of Green Chemical Engineering, School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou City, Jiangsu, 215123, P.R. China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Lei
authors.affiliation: Suzhou Key Laboratory of Green Chemical Engineering, School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou City, Jiangsu, 215123, P.R. China.
authors.forename: Xiao Dong
authors.initials: XD
authors.lastname: Chen
authors.affiliation: Suzhou Key Laboratory of Green Chemical Engineering, School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou City, Jiangsu, 215123, P.R. China.
authors.forename: Ruben
authors.identifier: http://orcid.org/0000-0003-0487-7400
authors.initials: R
authors.lastname: Mercadé-Prieto
mesh_terms: D000468:Alkalies / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry*; D005033:Ethylmaleimide / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D044367:Phase Transition; D012212:Rheology; D000067816:Whey Proteins / Q000737:chemistry*
chemical_list: D000468:Alkalies; D003432:Cross-Linking Reagents; D004220:Disulfides; D005782:Gels; D000067816:Whey Proteins; D005033:Ethylmaleimide