title: Engineering of caseins and modulation of their structures and interactions.
abstract: Beta-casein (beta-CN) is a milk protein widely used in food industries because of its mild emulsifying properties due to its amphiphilicity. However, the elements determining its micellization behavior in solution and interfacial behavior at the air-water interface are not well known. In order to study how the forced dimerisation influences functional properties of beta-CN, recombinant wild-type beta-CN was produced and distal cysteinylated forms of recombinant beta-CN were engineered. We show that 1) cysteinylated beta-CN formed mainly dimers bridged by disulfide bonds; 2) the process of dimerization adds to the micellization process with temperature and is poorly reversible; 3) covalent disulfide linkage forms at the air-water interface at a lower temperature than in bulk. In conclusion, the location of the cysteinylation in the C-terminus or N-terminus or both is of importance for the properties of beta-CN.
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Gaudin
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France.
authors.forename: Annabelle
authors.initials: A
authors.lastname: Le Parc
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Castrec
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Ropers
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France.
authors.forename: Yvan
authors.initials: Y
authors.lastname: Choiset
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France; Belozersky Institute of Physico-Chemical Biology, Moscow State University, Lenin's Hills, Moscow, 119992, Russia.
authors.forename: Juliya
authors.initials: J
authors.lastname: Shchutskaya
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France; Department of Biology, College of Sciences, Shiraz University, Shiraz, 71454, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Yousefi
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Moscow State University, Lenin's Hills, Moscow, 119992, Russia.
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Muronetz
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Kazan, P.O. Box 30, 420111, Russia.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Zuev
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Chobert
authors.affiliation: UR 1268 Biopolymères Interactions Assemblages, INRA, 44300 Nantes, France. Electronic address: haertle@nantes.inra.fr.
authors.forename: Thomas
authors.initials: T
authors.lastname: Haertlé
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002364:Caseins / Q000737:chemistry* / Q000378:metabolism; D017931:DNA Primers; D004220:Disulfides / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D011487:Protein Conformation; D015202:Protein Engineering; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
chemical_list: D002364:Caseins; D017931:DNA Primers; D004220:Disulfides