Proteomic Analysis of Hair Shaft and Nail Plate

The study conducted a proteomic analysis of the hair shaft and nail plate, revealing that most proteins, primarily keratins and keratin-associated proteins, could be extracted under denaturing conditions, although 15-20% remained intractable due to cross-linking. Shotgun proteomics allowed for the identification of over 300 protein constituents and certain post-translational modifications, indicating that the cross-linking process effectively utilized available resources to create mechanically stable structures. This proteomic knowledge provided a basis for correlating hair shaft structural defects with protein deficiencies and could be extended to mouse models, suggesting potential variations in human populations. The nail plate was also analyzed using this approach, offering noninvasive sampling of the human proteome with potential diagnostic utility for certain diseases.