The amino acid sequence of cytochrome c from the locust, Schistocerca gregaria Forskal

Complete amino-acid sequences of two isocytochromes c of the housefly, Musca domestica L., and their developmental variation in different tissues

The complete amino-acid sequences of two isocytochromes c (larval- and adult-type cytochromes c) purified from the housefly Musca domestica L. were determined. Their sequences differed at six positions from each other. More than 90% of the total cytochrome c was larval-type during larval stages. The amount of adult-type cytochrome c increased rapidly from 1 day before adult emergence, making the total cytochrome c content increase to approximately 2.5-times as much cytochrome c content as in larvae. Although the major cytochrome c species in flight muscles was adult-type, imaginal disks contained mainly larval-type cytochrome c.

Evolutionary changes in protein composition -- evidence for an optimal strategy

The information contained in the composition of different proteins of the same family is analyzed. It is found that within each family the gain in information per amino acid replacement is constant. This finding is interpreted to imply that evolutionary changes in proteins follow an "optimal" path in the sense that they maximize the number of potentially functional sequences that can be generated by T accepted point mutations from a given protein, subject to restrictions due to biological function.

Evolutionary change in invertebrate cytochrome C

Recently published amino acid sequences are compared to those of other cytochromes c. Molecular phylogenies constructed by using an ancestral sequence method are compared to the classical biological view of invertebrate evolution. Problems associated with the analysis of sequences of different chain lengths and of high variability are discussed, and the logistics of increasing the representation of key invertebrate phyla is assessed.