Age-Associated Changes in Bovine Muscle Connective Tissue. I. Rate of Hydrolysis by Collagenasea

Authors

  • DARREL E. GOLL,

    1. Department of Biochemistry and Department of Meat and Animal Science, Cooperating University of Wisconsin Madison, Wisconsin
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    • b

      Department of Dairy and Food Industry, Iowa State University, Ames, Iowa.

  • W. G. HOEKSTRA,

    1. Department of Biochemistry and Department of Meat and Animal Science, Cooperating University of Wisconsin Madison, Wisconsin
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  • R. W. BRAY

    1. Department of Biochemistry and Department of Meat and Animal Science, Cooperating University of Wisconsin Madison, Wisconsin
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  • a

    This paper, taken from the Ph.D. thesis of Darrel E. Goll (University of Wisconsin, 1962), was presented in part before the 54th Annual Meeting of the American Society of Animal Production, Chicago, November, 1962. Published with the approval of the Wisconsin Agricultural Experiment Station.

SUMMARY

Age-associated structural changes in collagenous residues isolated from the loose connective-tissue network found within bovine biceps femoris muscle were studied with collagenase used as a structural probe. Rate of enzymatic digestion was measured by following the release of soluble protein, hydroxyproline, and ninhydrin-positive material into the medium surrounding the fibrous residues. Under the conditions of the experiment, 8–11% of the protein and 8–21% of the hydroxyproline in the residues were solubilized after 12 hr of incubation with collagenase. Samples from four age groups were studied: Group I, veal, 40–49 days old; Group II, steers, 403–495 days old; Group III, cows, 4 years, 8 months to 5 years, 5 months old; Group IV, aged cows, 10 years, 2 months and 10 years, 5 months old. The groups ranked I, III, IV, and II, from fastest to slowest, in rate of hydrolysis by collagenase. However, it was postulated that the larger amounts of lipid associated with the Group II samples acted to shield collagenase-labile bonds and cause a slow rate of hydrolysis. Making this assumption, it appears that susceptibility to collagenase digestion of loose connective tissue follows an age pattern similar to that reported for skin and tendon collagen.

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