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Hydrophobic surface areas and net charges of αs1-, κ-casein and αs1-casein: κ-casein complex

Published online by Cambridge University Press:  01 June 2009

Shun'ichi Dosako
Affiliation:
Technical Research Institute, Snow Brand Milk Products Co., Ltd, 1–2 Minamidai 1-chome, Kawagoe, 350, Japan
Shuichi Kaminogawa
Affiliation:
Department of Agricultural Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
Shin'ichi Taneya
Affiliation:
Technical Research Institute, Snow Brand Milk Products Co., Ltd, 1–2 Minamidai 1-chome, Kawagoe, 350, Japan
Kunio Yamauchi
Affiliation:
Department of Agricultural Chemistry, The University of Tokyo, Bunkyo-ku, Tokyo, Japan

Summary

Hydrophobic surface areas of αs1- and κ-casein polymers and αs1-casein: κ-casein complex were estimated by the salting-out technique using various salts according to the theory of Melander & Horvath (1977). Calculated hydrophobic surface areas of αs1, κ-casein polymers and αs1-casein: κ-casein complex were 1976, 3571 and 2989 Å2 respectively. Assuming that κ-casein polymer dissociated into 4 particles in complex formation and that 1 mole of αs1-casein: κ-casein complex was produced from 2 mole of αs1-casein polymer and one of these dissociated κ-casein particles, the hydrophobic surface area of αs1-casein: κ-casein complex was less than those of 2 mole of αs1-casein polymer plus a quarter κ-casein polymer. On the other hand, the net charge of αs1-casein: κ-casein complex was nearly equal to that of 2 mole of αs1-casein polymer plus a quarter of κ-casein polymer. From these results, it was concluded that the complex formation of αs1- and κ-casein polymers was hydrophobic and that electrostatic interaction did not participate in complex formation.

Type
Original Articles
Copyright
Copyright © Proprietors of Journal of Dairy Research 1980

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References

REFERENCES

Chiba, H., Tatsumi, K., Sasaki, R. & Sugimoto, E. (1970). Nippon Nôgeikagaku Kaishi 44, 371379.CrossRefGoogle Scholar
Clarke, R. & Nakai, S. (1971). Biochemistry 10, 33533357.CrossRefGoogle Scholar
Dosako, S., Kaminooawa, S. & Yamauchi, K. (1975). Agricultural and Biological Chemistry 39, 23472351.Google Scholar
Dosako, S., Kaminooawa, S. & Yamauchi, K. (1979). Agricultural and Biological Chemistry 43, 10371041.Google Scholar
Edsall, J. T. & Wyman, J. (1958). Biophysical Chemistry, vol. I, pp. 282296. New York: Academic Press.Google Scholar
Kaminooawa, S., Dosako, S. & Yamauchi, K. (1974). Agricultural and Biological Chemistry 38, 23372341.Google Scholar
Kaminooawa, S., Dosako, S., Yamauchi, K. & Kinoshita, K. (1975). Agricultural and Biological ChemiStry 39, 533539.Google Scholar
Melander, W. & Horváth, C. (1977). Archives of Biochemistry and Biophysics 183, 200215.CrossRefGoogle Scholar
Morgan, J. L. R. & Mckirahan, W. W. (1913). Journal of the American Chemical Society 35, 17591770.CrossRefGoogle Scholar
Nakai, S., Wilson, H. K. & Herreid, E. O. (1967). Journal of Dairy Science 50, 456460.CrossRefGoogle Scholar
Payens, T. A. J. (1966). Journal of Dairy Science 49, 13171324.CrossRefGoogle Scholar
Pepper, L. (1972). Biochimica et Biophysica Acta 278, 147154.CrossRefGoogle Scholar
Tanford, C. (1961). In Physical Chemistry of Macromolecules, pp. 467482. New York: Wiley.Google Scholar
Wauqh, D. F. (1971). In Milk Proteins, vol. II, pp. 385. (Ed. McKenzie, H. A..) New York: Academic Press.CrossRefGoogle Scholar
Waugh, D. F. & von Hippel, P. H. (1956). Journal of the American Chemical Society 78, 45764582.CrossRefGoogle Scholar
Yoshikawa, M., Sugimoto, E. & Chiba, H. (1974). Agricultural and Biological Chemistry 38, 10051013.CrossRefGoogle Scholar