ISSN:
1435-1536
Keywords:
Caseins
;
milk micelles
;
small angle neutron scattering
;
dynamic light scattering
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Casein is the main protein component of milk and is of remarkable colloidal stability. Under the influence of milk clotting enzymes casein shows the striking behaviour of coagulation. This clotting process has already been studied by other groups, neglecting the fact that casein is not a homogeneous protein. The purpose of the present study is focused, in this first stage, on the determination of the structure of the various casein components. In cooperation with other laboratories we have been able to obtain the well separated individual proteins. Studies have been performed so far withβ- andχ-casein. For detailed structural information we carried out small angle neutron scattering and combined static and dynamic light scattering measurements and determined the molecular weight,M w, the radius of gyration, 〈S 2〉 the hydrodynamic radius,R H, theϱ-value and the particle scattering factor, Pz(q). The two caseins show a strikingly different behaviour. For theβ-casein we found a star-like structure, i. e. an aggregation pattern that is expected for a common micelle. The micelle consists of about 38 monomer chains. The aggregates ofχ-casein appear to be composed of star-like submicelles, where each submicelle contains nineχ-casein chains and the total degree of aggregation is about 140.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01425026
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