title: Self-assembly of beta-casein and lysozyme.
abstract: The self-assembly of beta-casein and lysozyme, a linear and a globular protein with isoelectric point of pH 5.0 and 10.7, respectively, was studied. Polydisperse electrostatic complex micelles formed when mixing beta-casein and lysozyme aqueous solutions. After the micelle solution was heated, lysozyme gelated and beta-casein was trapped in the gel, producing narrowly dispersed nanoparticles. The nanoparticles were characterized with laser light scattering, zeta-potential, steady state fluorescence, atomic force microscopy, and transmission electron microscopy. The nanoparticles have spherical shape and their sizes depend on the pH of the heat treatment and the molar ratio of beta-casein to lysozyme. The nanoparticles display amphoteric property and are relatively hydrophobic at pH around 5 and around 10. The net charges on the surface stabilize the nanoparticles in the solution.
authors.affiliation: The Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Pan
authors.forename: Shaoyong
authors.initials: S
authors.lastname: Yu
authors.forename: Ping
authors.initials: P
authors.lastname: Yao
authors.forename: Zhengzhong
authors.initials: Z
authors.lastname: Shao
mesh_terms: D002364:Caseins / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D009113:Muramidase / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D012965:Sodium Chloride / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D055672:Static Electricity; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D002364:Caseins; D008823:Micelles; D012996:Solutions; D014867:Water; D012965:Sodium Chloride; D009113:Muramidase