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Kinetics of rennin action on casein prepared by ultracentrifugation

Published online by Cambridge University Press:  01 June 2009

A. V. Castle
Affiliation:
School of Biological Sciences, The University, Bradford, Yorkshire BD7 1DP
J. V. Wheelock
Affiliation:
School of Biological Sciences, The University, Bradford, Yorkshire BD7 1DP

Summary

The kinetics of the primary phase of rennin action on casein micelles and on total casein prepared by ultracentrifugation have been studied. It was observed that the values of Km and V varied for the different casein samples. Addition of whey proteins to the reaction mixture or variation of the concentrations of Na+ and K+ had no effect on Km and V and V, but there was a consistent increase in the values of both these parameters when κ-casein was added. It was concluded that these changes were due to an increase in the accessibility of the κ-casein resulting from the rearrangement of the casein micelles. These results are in agreement with our earlier conclusion that the Km for rennin action on casein is dependent on the carbohydrate composition of the molecule.

Type
Research Article
Copyright
Copyright © Proprietors of Journal of Dairy Research 1973

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References

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