ISSN:
1476-5535
Keywords:
Casein
;
Solubility profile
;
Primary structure
;
Posttranslational modification
;
Protein functionality
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Summary Molecular biology holds the promise of new tools for the food industry which include proteins with tailor-made functionality. Without a fundamental knowledge of the molecular bases of these properties, implementation will be strictly empirical. For example, the phenomena of salt-induced precipitation of proteins (salting-out) and their resolubilization (salting-in) has heretofore been discussed only qualitatively. A quantitative method, using Wyman's theory of thermodynamic linkage, has been developed and tested on the calcium-induced solubility profiles of the major milk proteins, the caseins. Salting-out was described by a salt-binding constant,k 1, andn, the number of moles of salt bound; salting-in was described by the corresponding termsk 2 andm. The magnitude of these parameters indicated involvement of protein phosphate groups in binding and precipitation, but enzymatic dephosphorylation showed significant increases ink 1 andk 2 indicating involvement of carboxylate groups as well. Studies on two genetic variants of αs1-casein indicated the importance of a hydrophobically stabilized intramolecular ion pair in the functionality of the protein. These studies have led to a fuller understanding of the molecular basis for the solubility behavior of caseins and have laid the groundwork for future computer simulation of food protein functionality.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01569548
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