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Hydrolysis of 14C-labelled proteins by rumen micro-organisms and by proteolytic enzymes prepared from rumen bacteria

Published online by Cambridge University Press:  09 March 2007

R. J. Wallace
R. J. Wallace
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
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Abstract

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1. Proteins were labelled with 14C in a limited reductive methylation using [14C]formaldehyde and sodium borohydride.

2. The rate of hydrolysis of purified proteins was little (< 10%) affected by methylation and the 14C-labelled digestion products were not incorporated into microbial protein during a 5 h incubation with rumen fluid in vitro. It was therefore concluded that proteins labelled with 14C in this way are valid substrates for study with rumen micro-organisms.

3. The patterns of digestion of 14C-labelled fish meal, linseed meal and groundnut-protein meal by rumen micro-organisms in vitro were similar to those found in vivo.

4. The rates of hydrolysis of a number of 14C-labelled proteins, including glycoprotein II and lectin from kidney beans (Phaseolus vulgaris), were determined with mixed rumen micro-organisms and with proteases extracted from rumen bacteria. Different soluble proteins were digested at quite different rates, with casein being most readily hydrolysed.

5. Proteins modified by performic acid oxidation, by cross-linking using 1,6-di-iso-cyanatohexane or by diazotization were labelled with 14C. Performic acid treatment generally increased the susceptibility of proteins to digestion, so that the rates of hydrolysis of performic acid-treated proteins were more comparable than those of the unmodified proteins. Cross-linking resulted in a decreased rate of hydrolysis except with the insoluble proteins, hide powder azure and elastin congo red. Diazotization had little effect on the rate of hydrolysis of lactoglobulin and albumin, but inhibited casein hydrolysis and stimulated the breakdown of γ-globulin.

Type
Papers on General Nutrition
Information
British Journal of Nutrition , Volume 50 , Issue 2 , September 1983 , pp. 345 - 355
Copyright
Copyright © The Nutrition Society 1983

References

REFERENCES

Annison, E. F. (1956). Biochemical Journal 64, 705–714.CrossRefGoogle Scholar
Blackburn, T. H. & Hobson, P. N. (1960 a). Journal of General Microbiology 22, 272–281.CrossRefGoogle Scholar
Blackburn, T. H. & Hobson, P. N. (1960 b). Journal of General Microbiology 22, 290–294.CrossRefGoogle Scholar
Brock, F. M., Forsberg, C. W. & Buchanan-Smith, J. G. (1982). Applied and Environmental Microbiology 44, 561–569.CrossRefGoogle Scholar
Dinsdale, D., Cheng, K.-J., Wallace, R. J. & Goodlad, R. A. (1980). Applied and Environmental Microbiology 39, 1059–1066.CrossRefGoogle Scholar
Forsberg, C. W. & Lam, K. (1977). Applied and Environmental Microbiology 33, 528–537.CrossRefGoogle Scholar
Hazlewood, G. P. & Edwards, R. (1981). Journal of General Microbiology 125, 11–15.Google Scholar
Kopecny, J. & Wallace, R. J. (1982). Applied and Environmental Microbiology 43, 1026–1033.CrossRefGoogle Scholar
Lowry, O. H., Rosebrough, N. J., Farr, A. L. & Randall, R. J. (1951). Journal of Biological Chemistry 193, 265–275.CrossRefGoogle Scholar
McDonald, I. W. (1954). Biochemical Journal 56, 120–125.CrossRefGoogle Scholar
Mahadevan, S., Erfle, J. D. & Sauer, F. D. (1979). Journal of Animal Science 48, 947–953.Google Scholar
Mahadevan, S., Erfle, J. D. & Sauer, F. D. (1980). Journal of Animal Science 50, 723–728.Google Scholar
Manen, J. F. & Pusztai, A. (1982). Planta 155, 328–334.Google Scholar
Mangan, J. L. (1972). British Journal of Nutrition 27, 261–283.Google Scholar
Means, G. E. & Feeney, R. E. (1971). Chemical Modification of Proteins. San Francisco: Holden-Day.Google Scholar
Nugent, J. H. A. & Mangan, J. L. (1978). Proceedings of the Nutrition Society 37, 48A.Google Scholar
Nugent, J. H. A. & Mangan, J. L. (1981). British Journal of Nutrition 46, 39–58.Google Scholar
Ørskov, E. R., Hughes-Jones, M. & McDonald, I. (1981). In Recent Advances in Animal Nutrition – 1980, pp. 85–98 [Haresign, W., editor] London: Butterworths.CrossRefGoogle Scholar
Ozawa, H. (1967). Journal of Biochemistry, Tokyo 62, 419–423.CrossRefGoogle Scholar
Pusztai, A. & Watt, W. B. (1970). Biochimica et Biophysica Acta 207, 413–431.CrossRefGoogle Scholar
Spiro, R. G. (1960). Journal of Biological Chemistry 235, 2860–2869.Google Scholar
Wallace, R. J. & Kopecny, J. (1983). Applied and Environmental Microbiology 45, 212–217.CrossRefGoogle Scholar