Letter | Published:

Intestinal Proteinases in an Insect, Calliphora vomitoria L.

Naturevolume 192pages9991000 (1961) | Download Citation



THE properties of the proteolytic enzymes occurring in extracts of insect guts are generally thought to resemble those of vertebrate trypsin1,2. Only proteinases of alkaline type, with maximum activity about pH 8, have been recorded in Calliphora adults3, Lucilia larvæ4, Musca larvæ5, Stomoxys adults6, and Calliphora larvæ7. The only workers td suggest that proteinases in Diptera–Cyclorrhapha do not conform to the general theory, Greenberg and Paretsky8, reported two distinct proteinases functioning in every stage of the life-cycle of Musca with pH optima at pH 3 and pH 8–9.

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  1. 1

    Day, M. F., and Waterhouse, D. F., Insect Physiology, edit. by Roeder (London, 1953).

  2. 2

    Gilmour, O., The Biochemistry of Insects (London, 1961).

  3. 3

    Wigglesworth, V. B., Parasitol., 21, 288 (1929).

  4. 4

    Hobson, R. P., J. Exp. Biol., 8, 109 (1931).

  5. 5

    Day, M. F., and Powning, R. F., Austral. J. Sci. Res., B, 2, 175 (1949).

  6. 6

    Champlain, R. A., and Fisk, F. W., Ohio J. Sci., 56, 52 (1956).

  7. 7

    Evans, W. A. L., Exp. Parasitol., 7, 69 (1958).

  8. 8

    Greenberg, B., and Paretsky, D., Ann. Ent. Soc. Amer., 48, 46 (1955).

  9. 9

    Waterhouse, D. F., Counc. Sci. Industr. Res Austral., Pamph. No. 102, 5 (1940).

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  1. Department of Zoology, University of Glasgow



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