Proteotypic peptides of hairs for the identification of common European domestic and wild animal species revealed by in‐sample protein digestion and mass spectrometry analysis

Abstract

The aim of this work is to offer an alternative or complementary analytical tool to the time-consuming and expensive methods commonly used for the recognition of animal species according to their hair. The paper introduces a simple and fast way for species differentiation of animal hairs called in-sample digestion. A total of 10 European animal species, including cat, cow, common degu, dog, fallow deer, goat, horse, sika deer, rabbit, roe deer, and 17 different breeds of dogs were examined using specific tryptic cleavage directly in hair followed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and liquid chromatography-electrospray ionization quadrupole time of flight. Principal component analysis was used for the subsequent mass spectrometric data evaluation. This novel approach demonstrates the ability to distinguish among individual animal species, which is supported by finding characteristic m/z values obtained by the mass spectrometry for each animal species. The approach was successfully tested on two "blind" samples. On the other hand, the attempt to distinguish among hairs of different dog breeds has not been successful due to the very similar protein composition and their amino acid sequences.

Characterization of vestibular schwannoma tissues using liquid chromatography‐tandem mass spectrometry analysis of specific peptide fragments separated by in‐sample tryptic protein digestion followed by mathematical analysis

“…This approach was successfully used even for the analysis of proteins entrapped in swine alveolar bones, as well as human maxillary and mandibular bones, in relation to the field of oral surgery [16][17][18]. Recently, the technique was applied to study various induced pathological states in human in vitro bone models [19], identification of common domestic and wild animal species in Europe according to their hair proteins [20], and characterization of eye corner tissues as well as human in vitro eye corner substitute [21]. In-sample digestion obviously represents a fast and highly effective approach, since it does not require complicated isolation of proteins from insoluble samples.…”