Rothnagel J A, Rogers G E
Mol Cell Biochem. 1984;58(1-2):113-9. doi: 10.1007/BF00240610.
The epsilon-(gamma-glutamyl)lysine isopeptide bond has been identified in certain structural proteins of the hair fibre and the epidermis. The major cross-linked proteins are not keratins and generally have little or no cysteine, but have a high glutamic acid/glutamine residue content. In the hair fibre the cross-link appears in the citrulline-containing proteins of the medulla and the inner root sheath of the follicle. In the epidermis the cross-linked proteins are involved in the formation of the cornified envelope of the stratum corneum cells. In both cases, the cross-linked proteins contribute the characteristic property of chemical resistance to their biological structures.
ε-（γ-谷氨酰基）赖氨酸异肽键已在毛发纤维和表皮的某些结构蛋白中被鉴定出来。主要的交联蛋白不是角蛋白，通常几乎不含或根本不含半胱氨酸，但谷氨酸/谷氨酰胺残基含量很高。在毛发纤维中，交联出现在毛囊髓质和内根鞘中含瓜氨酸的蛋白质中。在表皮中，交联蛋白参与角质形成细胞角质包膜的形成。在这两种情况下，交联蛋白都为其生物结构赋予了耐化学性这一特性。
