Ikai K, McGuire J S
Arch Dermatol Res. 1986;278(5):367-71. doi: 10.1007/BF00418164.
The biochemical characteristics of cyclic AMP-dependent protein kinase in calf-snout epidermis were investigated. The activity of cyclic AMP-dependent protein kinase was higher in the lower layer than the upper layer of epidermis. The supernatant of homogenates of the lower layer of calf-snout epidermis was fractionated by DEAE-cellulose chromatography and contained two major peaks of protein kinase activity stimulated by cyclic AMP. This chromatographic pattern is similar to that referred to as Type I and Type II of cyclic AMP-dependent protein kinase in bovine muscle. Both peaks of cyclic AMP-dependent protein kinase in calf-snout epidermis could phosphorylate keratin polypeptides in vitro. The phosphorylation reaction was activated by cyclic AMP and inhibited by a heat-stable inhibitor of cyclic AMP-dependent protein kinase. When Type II enzyme of cyclic AMP-dependent protein kinase was incubated with [gamma-32P]ATP in the absence of substrates, such as histone or keratin polypeptides, the 54,000 dalton protein was phosphorylated and this autophosphorylation was inhibited by the addition of 10 microM cyclic AMP. These results suggest that cyclic AMP-dependent protein kinase in calf-snout epidermis has properties similar to those in bovine muscle and plays an important role in the phosphorylation of keratin polypeptides in calf-snout epidermis.
对小牛鼻表皮中依赖环磷酸腺苷的蛋白激酶的生化特性进行了研究。依赖环磷酸腺苷的蛋白激酶的活性在表皮下层高于上层。小牛鼻表皮下层匀浆的上清液经二乙氨基乙基纤维素色谱分离，含有两个由环磷酸腺苷刺激的蛋白激酶活性主峰。这种色谱模式与牛肌肉中依赖环磷酸腺苷的蛋白激酶的I型和II型相似。小牛鼻表皮中依赖环磷酸腺苷的蛋白激酶的两个峰均可在体外磷酸化角蛋白多肽。磷酸化反应由环磷酸腺苷激活，并被依赖环磷酸腺苷的蛋白激酶的热稳定抑制剂抑制。当依赖环磷酸腺苷的蛋白激酶的II型酶在没有底物（如组蛋白或角蛋白多肽）的情况下与[γ-32P]ATP一起孵育时，54,000道尔顿的蛋白被磷酸化，并且这种自磷酸化被添加10微摩尔环磷酸腺苷所抑制。这些结果表明，小牛鼻表皮中依赖环磷酸腺苷的蛋白激酶具有与牛肌肉中相似的特性，并在小牛鼻表皮角蛋白多肽的磷酸化中起重要作用。
