Gniadecka M, Faurskov Nielsen O, Christensen D H, Wulf H C
Department of Dermatology, Bispebjerg Hospital, University of Copenhagen, Denmark.
J Invest Dermatol. 1998 Apr;110(4):393-8. doi: 10.1046/j.1523-1747.1998.00146.x.
Raman spectroscopy is a nondestructive analytical method for determining the structure and conformation of molecular compounds. It does not require sample preparation or pretreatment. Recently, near-infrared Fourier transform Raman spectroscopy has emerged as being specially suited for investigations of biologic material. In this study, we obtained near-infrared Fourier transform Raman spectra of intact human skin, hair, nail, and stratum corneum. We disclosed major spectral differences in conformational behavior of lipids and proteins between normal skin, hair, and nail. The amide I and III band location indicated that the majority of proteins in all samples have the same secondary alpha-helix structure. Positions of (S-S) stretching bands of proteins revealed a higher stability of the disulfide bonds in the hair and the nail. Analysis of vibrations of protein -CH groups showed that in the hair and the nail the proteins are apparently highly folded, interacting with the surroundings only to a small degree. The position of lipid specific peaks in spectra of hair, nail, and stratum corneum suggested a highly ordered, lamellar crystalline lipid structure. A greater lipid fluidity was found in whole skin. Assessment of the structure of water clusters revealed that mainly bound water is present in the human skin, stratum corneum, and nail. In conclusion, structural changes of water, proteins, and lipids in intact skin and skin appendages may be analyzed by Raman spectroscopy. This technique may be used in the future in a noninvasive analysis of structural changes in molecular compounds in the skin, hair, and nail associated with different dermatologic diseases.
拉曼光谱法是一种用于确定分子化合物结构和构象的无损分析方法。它不需要样品制备或预处理。最近，近红外傅里叶变换拉曼光谱法已成为特别适合研究生物材料的方法。在本研究中，我们获得了完整的人类皮肤、头发、指甲和角质层的近红外傅里叶变换拉曼光谱。我们揭示了正常皮肤、头发和指甲中脂质和蛋白质构象行为的主要光谱差异。酰胺I和III带的位置表明所有样品中的大多数蛋白质具有相同的二级α-螺旋结构。蛋白质的（S-S）伸缩带位置显示头发和指甲中的二硫键具有更高的稳定性。对蛋白质-CH基团振动的分析表明，头发和指甲中的蛋白质明显高度折叠，与周围环境的相互作用程度很小。头发、指甲和角质层光谱中脂质特异性峰的位置表明存在高度有序的层状结晶脂质结构。在全皮肤中发现了更大的脂质流动性。对水簇结构的评估表明，人类皮肤、角质层和指甲中主要存在结合水。总之，完整皮肤和皮肤附属器中水、蛋白质和脂质的结构变化可以通过拉曼光谱法进行分析。该技术未来可用于无创分析与不同皮肤病相关的皮肤、头发和指甲中分子化合物的结构变化。
