Buxman M M, Wuepper K D
J Invest Dermatol. 1975 Jul;65(1):107-12. doi: 10.1111/1523-1747.ep12598072.
Enzymes known as transglutaminases mediate cross-linking of polypeptide chains by epsilon-(gamma-glutamyl) lysine bonds. Such bonds stabilize structural proteins of many tissues; transglutaminases specific for these tissues have been identified. A calcium- and sulfhydryl-dependent transglutaminase with a molecular weight of 55,000 has been purified from bovine snout epidermis and used to elicit a specific antiserum to the enzyme. Sites of epidermal transglutaminase activity have been localized in the cytoplasm of upper malpighian and granular cells by two complementary methods. When thin-tissue sections were incubated with a fluorescent lysine analog(dansyl cadaverine) and calcium, tissue acceptor sites became fluorescent. Localization was confirmed by fluorescein-conjugated antibody labeling of the enzyme in situ. These observations indicate that epidermal transglutaminase cross-links epidermal proteins during the final stages of keratinization.
被称为转谷氨酰胺酶的酶通过ε-（γ-谷氨酰基）赖氨酸键介导多肽链的交联。此类键稳定许多组织的结构蛋白；已鉴定出针对这些组织的特异性转谷氨酰胺酶。一种分子量为55,000的钙和巯基依赖性转谷氨酰胺酶已从牛鼻表皮中纯化出来，并用于制备针对该酶的特异性抗血清。表皮转谷氨酰胺酶活性位点已通过两种互补方法定位在上皮角质形成细胞和颗粒细胞的细胞质中。当薄组织切片与荧光赖氨酸类似物（丹磺酰尸胺）和钙一起孵育时，组织受体位点会发出荧光。通过酶的荧光素偶联抗体原位标记证实了定位。这些观察结果表明，表皮转谷氨酰胺酶在角质化的最后阶段交联表皮蛋白。
