Proteome Analysis of Human Hair Shaft

The study conducted a proteome analysis of the human hair shaft using two-dimensional LC-MS/MS, identifying 343 proteins. Among these, 70 proteins, including keratin intermediate filament proteins, were found in high abundance and were largely extractable with denaturants. Over 300 proteins were part of an insoluble complex formed by transglutaminase cross-linking. The proteins identified were distributed across various cellular locations, including the cytoplasm, nucleus, mitochondria, ribosome, and plasma membrane. The study provided insights into the ultrastructural features of mature hair, noting posttranslational modifications such as methylation, dimethylation, and evidence of ubiquitination in hair proteins.