Peptidyl Acylating Agents in the Pupae of Drosophila melanogaster and their Possible Relationship to Protein Synthesis

Citation

Cole, Thomas Alan (1963) Peptidyl Acylating Agents in the Pupae of Drosophila melanogaster and their Possible Relationship to Protein Synthesis. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/3V4P-DY85. https://resolver.caltech.edu/CaltechTHESIS:02232012-162634131

Abstract

The effects of hydroxylamine and tyrosine on homogenates of early Drosophila pupae have been studied by several criteria. Both low speed and high speed supernatants of the homogenized pupae give positive tests for hydroxamic acids after incubation with hydroxylamine. A comparison of the hydroxamic acid forming abilities of the supernatants shows that the low speed supernatant is the more active and that tyrosine increases hydroxamate formation in the low speed but not in the high speed supernatants.

Both hydroxylamine and tyrosine have definite effects on alkaline phosphatase activity in the low speed supernatant. Tryosine causes an increase in the activity upon incubation at 0°C and 25°C. Hydroxylamine decreases the activity regardless of the temperature or the presence of tyrosine.

Both tyrosine and hydroxylamine affect the distribution of ninhydrin-positive compounds of dialyzates of low speed supernatants. Hydroxylamine effectively reduces the amount of the acidic components, but its effect is slightly modified by tyrosine. The presence of tyrosine alone increases the amount of acidic materials as compared to the untreated sample. In general, the ninhydrin-positive compounds are more sensitive to the presence of hydroxylamine than of tyrosine.

Some preliminary work on the nature of the compounds in question shows that they contain more than one amino acid. The data on the nature of these compounds is consistent with the proposition that peptidyl hydroxamates are the Fe ^(+++)- positive materials.

Naturally-occurring peptides and the current understanding of protein synthesis are reviewed. The possibility that peptides per se are incorporated into the proteins in Drosophila pupae is discussed and mechanisms for this possibility are explored.

Thesis Files