Studies on the biochemistry of insects. X. Data on protein metabolism in the metamorphosis of Calliphora erythrocephala

Abstract

The total proteins in all the phases of the metamorphosis of Calliphora erythrocephala, are being studied here by the Microkjeldahl and Lowry photocolorimetric methods. We have observed that from the larval phase to the imago, the total decrease is of 26.60 %, this diminution being three times higher when passing from pupa to imago than from larva to pupa.

We have also performed the analysis, by paper electrophorese, of the proteic fractions through the metamorphosis, revealing the presence of two fractions remaining during all the development but the fluctuations of which are characteristic of each phase and suggest the influence of basic growth activities. We have also determined the isoelectric point of the quickest fraction.

By means of photocolorimetric techniques we have also studied the metabolism of phenilalanine, tyrosine and triptophane in the three phases of the metamorphosis. Of these, phenilalanine is the one predominating in all phases, then comes in order of proportion, tyrosine and next triptophane, except in the larva where tyrosine predominates, which suggests the synthesis of this aminoacid from the first. Triptophane decreases on passing from larva to pupa and increases again in the imago which may be due to an endogenous synthesis of this aminoacid during pupation.