Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-29T12:50:32.375Z Has data issue: false hasContentIssue false

Rates of proteolysis in the rumen of the soluble proteins casein, Fraction I (18S) leaf protein, bovine serum albumin and bovine submaxillary mucoprotein

Published online by Cambridge University Press:  09 March 2007

J. H. A. Nugent
Affiliation:
Biochemistry Department, ARC Institute of Animal Physiology, Babraham, Cambridge CB2 4AT
W. T. Jones
Affiliation:
Biochemistry Department, ARC Institute of Animal Physiology, Babraham, Cambridge CB2 4AT
D. J. Jordan
Affiliation:
Biochemistry Department, ARC Institute of Animal Physiology, Babraham, Cambridge CB2 4AT
J. L. Mangan
Affiliation:
Biochemistry Department, ARC Institute of Animal Physiology, Babraham, Cambridge CB2 4AT
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. The rate of proteolysis in the rumen was dependent on the soluble protein used. With a sheep on a hay + concentrate diet the rates (approximately Vmax) for casein, Fraction I leaf protein and bovine serum albumin were 16·5, 3·4 and 0·9 mg protein nitrogen/l per min respectively.

2. Change of diet from hay + concentrate to fresh lucerne (Medicago sativa) increased the proteolytic rates for all three proteins.

3. Bovine submaxillary mucoprotein degraded extremely slowly in the rumen at approximately 0·5–0·6 mg N/l per min and its sialic acid component was degraded at a similar rate to that of the protein chain.

4. Uniformly14C-labelled Fraction I leaf protein was used to demonstrate that in the presence of a second protein, competition for enzymic sites occurred. In Fraction I and bovine serum albumin mixtures, reduced rates for the individual proteins of the mixture were observed compared with the proteins treated separately.

5. Treatment of bovine serum albumin with dithiothreitol (0·2 g/l) to cleave disulphide bridges increased the rates of proteolysis by as much as 8·5-fold.

Type
Papers on General Nutrition
Copyright
Copyright © The Nutrition Society 1983

References

REFERENCES

Black, J. L., Beever, D. E., Faichney, G. J., Howarth, B. R. & Graham, N. McC. (1981). Agricultural Systems 6, 195220.CrossRefGoogle Scholar
Broderick, G. A. (1978). Journal of Nutrition 108, 181190.Google Scholar
Burroughs, W., Trenkle, A. & Vetter, R. L. (1971). Veterinary Medicine and Small Animal Clinician 66, 238247.Google Scholar
Chen, R. F. (1967). Journal of Biological Chemistry 242, 173181.CrossRefGoogle Scholar
Demeyer, D. I. & Van Nevel, C. J. (1980). Proceedings of the Nutrition Society 39, 8995.CrossRefGoogle Scholar
Ershoff, B. H., Wildman, S. G. & Kwanyuan, P. (1978). Proceedings of the Society of Experimental Biology and Medicine 157, 623630.Google Scholar
Gottschalk, W. (1960). Nature 186, 949951.CrossRefGoogle Scholar
Hazlewood, G. P. & Edwards, R. (1981). Journal of General Microbiology 125, 1115.Google Scholar
Hazlewood, G. P. & Nugent, J. H. A. (1978). Journal of General Microbiology 106, 369371.CrossRefGoogle Scholar
Henderickx, H. & Martin, J. (1963). Compte Rendu de Recherches, IRSIA, Brussels 31, 1166.Google Scholar
Hyden, S. (1956). Kungliga Lantbruckshogskolans Annalen 22, 139145.Google Scholar
Jones, W. T., Lyttleton, J. W. & Mangan, J. L. (1978). New Zealand Journal of Agricultural Research 21, 401407.CrossRefGoogle Scholar
Jones, W. T. & Mangan, J. L. (1976). Journal of Agricultural Science, Cambridge 86, 495501.CrossRefGoogle Scholar
Jones, W. T. & Mangan, J. L. (1977). Journal of the Science of Food and Agriculture 28, 126136.CrossRefGoogle Scholar
Lyttleton, J. W. (1964). New Zealand Journal of Agricultural Research 7, 228237.CrossRefGoogle Scholar
McDonald, I. W. & Hall, R. J. (1959). Biochemical Journal 67, 400405.Google Scholar
McDougall, E. I. (1948). Biochemical Journal 43, 99109.CrossRefGoogle Scholar
Mahadevan, S., Erfle, J. D. & Sauer, F. D. (1980). Journal of Animal Science 50, 723728.Google Scholar
Mangan, J. L. (1972). British Journal of Nutrition 27, 261283.CrossRefGoogle Scholar
Mangan, J. L., Jones, W. T., Nugent, J. H. A. & Jordan, D. J. (1977). Proceedings of the 11th Federation of European Biochemical Societies Meeting, Copenhagen A 3–2, 903.Google Scholar
Mangan, J. L. & West, J. (1977). Journal of Agricultural Science, Cambridge 89, 315.CrossRefGoogle Scholar
Miller, E. R.Balch, C. C., Ørskov, E. R., Roy, J. H. B. & Smith, R. H. (1977). Proceedings 2nd International Symposium on Protein Metabolism and Nutrition, p. 137. Wagenigen: Pudoc.Google Scholar
Nugent, J. H. A. & Mangan, J. L. (1978). Proceedings of the Nutrition Society 37, 48AGoogle Scholar
Nugent, J. H. A. & Mangan, J. L. (1981). British Journal of Nutrition 46, 3958.CrossRefGoogle Scholar
Ørskov, E. R., Mills, C. F. & Robinson, J. J. (1980). Proceedings of the Nutrition Society 39, 60AGoogle Scholar
Reid, M. S. & Beileski, R. L. (1968). Analytical Biochemistry 22, 374381.CrossRefGoogle Scholar
Roy, J. B. H., Balch, C. C., Miller, E. L., Ørskov, E. R. & Smith, R. H. (1977). Proceedings 2nd International Symposium on Protein Metabolism and Nutrition, p. 126. Wagenigen: Pudoc.Google Scholar
Svennerholm, L. (1957). Biochimica et Biophysica Acta 24, 604611.CrossRefGoogle Scholar