Studies on the Proteome of Human Hair - Identification of Histones and Deamidated Keratins

Abstract

Human hair is laminar-fibrous tissue and an evolutionarily old keratinization product of follicle trichocytes. Studies on the hair proteome can give new insights into hair function and lead to the development of novel biomarkers for hair in health and disease. Human hair proteins were extracted by detergent and detergent-free techniques. We adopted a shotgun proteomics approach, which demonstrated a large extractability and variety of hair proteins after detergent extraction. We found an enrichment of keratin, keratin-associated proteins (KAPs), and intermediate filament proteins, which were part of protein networks associated with response to stress, innate immunity, epidermis development, and the hair cycle. Our analysis also revealed a significant deamidation of keratin type I and II, and KAPs. The hair shafts were found to contain several types of histones, which are well known to exert antimicrobial activity. Analysis of the hair proteome, particularly its composition, protein abundances, deamidated hair proteins, and modification sites, may offer a novel approach to explore potential biomarkers of hair health quality, hair diseases, and aging.

Sensitive Method for the Confident Identification of Genetically Variant Peptides in Human Hair Keratin

“…Using both spectral library and Sequest searching methods, the results derived from F1 to F10 are compared in Table 1. As shown in Table 1, when the "main" library was combined with the "hair" library for spectral library searching, the overall library identification for proteins-for both hair proteome (7,9) and hair cuticular keratins (a major subset of the hair proteome) (1,8)was similar to that from Sequest; however, for all peptides identified, the spectral library method was somewhat more sensitive at a given FDR level, consistent with previous observations (14).…”

“…To detect them, we first need an efficient method to extract proteins from human hair shafts. However, hair protein extraction is especially difficult due to extensive cross‐linking and poor solubility of hair keratins . In this manuscript, we describe a direct protein extraction method (referred as the direct method) that can efficiently extract hair proteins from a single hair shaft less than 1 cm in length.…”

“…To detect them, we first need an efficient method to extract proteins from human hair shafts. However, hair protein extraction is especially difficult due to extensive cross-linking and poor solubility of hair keratins (7)(8)(9).…”

Ionisation bias undermines the use of matrix‐assisted laser desorption/ionisation for estimating peptide deamidation: Synthetic peptide studies demonstrate electrospray ionisation gives more reliable response ratios

“…2 Deamidation measurements provide a versatile tool for the investigation of protein stability and diagenetic changes. It is therefore not surprising that deamidation has been used in a broad range of research areas, from modern medicinal applications such as those in biotherapeutics, 3 to the investigation of deamidation products in relation to protein aging, such as α-crystallin in eye proteins, 4,5 studies on the proteome of human hair, 6 shotgun proteomic applications assessing deamidation in complex biological samples 7 antibody and peptide therapies, 8,9 as well as more recent applications such as the use of hydrogen/deuterium exchange mass spectrometry (HDX-MS) to investigate the effects of deamidation on monoclonal antibody structural confirmations. 10 In addition to this there have been a wide range of archaeological applications, with proteins recovered from ancient artefacts from sites as old as 3.8 million years in age.…”

Archaeological human hair in a burial context: Microscopical evaluation of samples from Iași, Romania (18th–19th centuries)

“…SEM is a useful approach for the assessment of the normal hair fibre and damage (Lucotte and Thomasset 2017;Adav et al 2018). It has revealed a variable degradation of the scalp hair by micro-organism activity (Fig.…”