Biocompatible micro-gel particles from cross-linked casein micelles.
The stability of internally cross-linked casein micelles against disruption by urea (which disrupts hydrogen bonds and hydrophobic interactions) and trisodium citrate (which sequesters micellar calcium phosphate) was investigated. Addition of urea (0-6 mol L-1) and/or citrate (0-50 mmol L-1) progressively reduced the turbidity of a suspension of casein micelles cross-linked by transglutaminase and increased particle size (determined by dynamic and static light scattering and small-angle neutron scattering), which was attributed to swelling of the micelles. Furthermore, model calculations, assuming a completely stable casein network, were performed to describe the decreases in turbidity on addition of urea and citrate. Measured and described turbidity values are in agreement, indicating that cross-linking of casein micelles with transglutaminase results in a covalently bound protein network, which is entirely stable to disruption by urea and/or citrate. This may offer potential applications for the use of cross-linked casein micelles as biocompatible protein micro-gel particles.
Huppertz
Thom
T
Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland. t.huppertz@uq.edu.au
Smiddy
Mary A
MA
de Kruif
Cornelis G
CG
D002364:Caseins / Q000737:chemistry*; D008823:Micelles; D033363:Neutron Diffraction; D010316:Particle Size; D053838:Scattering, Small Angle; D011503:Transglutaminases / Q000737:chemistry
D002364:Caseins; D008823:Micelles; D011503:Transglutaminases