Electrophoretic analysis of non-human primates hair keratin

Abstract

Keratin characterization through electrophoretic techniques has been used for species identification in forensic science and in taxonomic studies. In the present work, protein components solubilized from hair of non-human primates were evaluated to investigate whether there is any species-specific pattern in an evolutionary perspective, by grossly comparing hair native keratins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF). Extracted hair keratins for all specimens were separated by SDS-PAGE into 2–3 polypeptide bands with apparent MW in the range 39–54 kDa and into 3–7 polypeptide bands with apparent MW in the range 10–35 kDa. With this technique it was possible to distinguish different suborders, different families of the same suborder, and, sometimes, different genera from the same family. On the contrary, it was not possible to distinguish different species of the same genus and different specimens of the same species. With IEF, extracted hair keratins were separated into about 30 polypeptide bands with p I values in the range of pH 3.9–7.7. IEF discriminates poorly between different samples. Only in specimens from Papio genus did we find an additional polypeptide band. In conclusion, we found that the differences between electrophoretic patterns are largest for animals that are not closely related while specimens of the same species have the same patterns.