Department of Chemistry, Division of Physical Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden.
Department of Chemistry and Molecular Biology, Biomedical Photonics, University of Gothenburg, SE-412 96 Gothenburg, Sweden.
Biomacromolecules. 2023 Jun 12;24(6):2661-2673. doi: 10.1021/acs.biomac.3c00131. Epub 2023 May 18.
Keratins are structural proteins that are abundant in human skin, nails, and hair, where they provide mechanical strength. In the present study, we investigate the molecular mobilities and structures of three keratin-rich materials with clearly different mechanical properties: nails, stratum corneum (upper layer of epidermis), and keratinocytes (from lower layer of epidermis). We use solid-state NMR on natural-abundance C to characterize small changes in molecular dynamics in these biological materials with close to atomistic resolution. One strong advantage of this method is that it detects small fractions of mobile components in a molecularly complex material while it simultaneously gives information on the rigid components in the very same sample. The molecular mobility can be linked to mechanical material properties in different conditions, including hydration or exposure to osmolytes or organic solvents. Importantly, the study revealed that the response to both hydration and addition of urea is clearly different for the nail keratin compared to the stratum corneum keratin. The comparative examination of these materials may provide a better understanding of skin diseases originating from keratin malfunction and contributes to the design and development of new materials.
角蛋白是一种在人类皮肤、指甲和头发中含量丰富的结构蛋白，为这些组织提供机械强度。在本研究中，我们研究了三种富含角蛋白且力学性能明显不同的材料的分子迁移率和结构：指甲、角质层（表皮上层）和角朊细胞（表皮下层）。我们使用天然丰度 C 的固态 NMR 对这些生物材料中的分子动力学进行了近原子分辨率的小变化特征分析。这种方法的一个优势是，它可以检测分子复杂材料中移动成分的小部分，同时提供同一样品中刚性成分的信息。在不同条件下，分子迁移率可与机械材料性能相关联，包括水合或暴露于渗透物或有机溶剂。重要的是，研究表明，与角质层角蛋白相比，指甲角蛋白对水合作用和添加尿素的响应明显不同。对这些材料的比较研究可能有助于更好地理解源于角蛋白功能障碍的皮肤疾病，并为新材料的设计和开发做出贡献。
