BIOCHEMICAL DEMONSTRATION AND IMMUNOHISTOCHEMICAL LOCALIZATION OF CALPAIN IN HUMAN-SKIN
BIOCHEMICAL DEMONSTRATION AND IMMUNOHISTOCHEMICAL LOCALIZATION OF CALPAIN IN HUMAN-SKIN
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DOI：
10.1111/1523-1747.ep12285556
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发表时间：
1986-04-01
影响因子：
6.5
通讯作者：
MURACHI, T
中科院分区：
文献类型：
--
作者：
MIYACHI, Y;YOSHIMURA, N;MURACHI, T
钙蛋白酶是一种钙离子依赖的细胞内非溶酶体半胱氨酸蛋白酶，本文研究了它在人皮肤中的生化特性和免疫组织化学定位。在DEAE-纤维素柱上分级分离人表皮钙蛋白酶I，发现在3.5 μ M游离Ca 2+下半最大活化，在10 μ M Ca 2+下完全活化，如通过酪蛋白水解测量的。钙蛋白酶的免疫电泳印迹显示，只有一个单一的带先生83,000，当印迹与亲和纯化的抗钙蛋白酶I重亚基IgG。正常人表皮的免疫组化染色显示，calpain I定位于角质形成细胞的细胞质中，而不是在基底细胞中的中上部表皮。在未治疗的银屑病表皮中，这种蛋白酶的沉积仅在角质层下方可见。然而，显着染色后观察到局部光化学疗法的peptien加长波紫外线照射。光化学疗法是否诱导了钙蛋白酶数量的定量增加，或者仅仅是通过改变细胞膜使钙蛋白酶更容易被激活，仍然是未知的。
The biochemical properties and immunohistochemical localization of calpain, a Ca2+-dependent, intracellular, nonlysosomal cysteine proteinase was examined in human skin. Human epidermal calpain I was fractionated on a DEAE-cellulose column and was found to be half-maximally activated at 3.5 .mu.M free Ca2+ and fully activated at 10 .mu.M Ca2+ as measured by casein hydrolysis. Immunoelectrophoretic blotting of calpain revealed only a single band of Mr 83,000, when the blot was made with affinity-purified anti-calpain I heavy subunit IgG. Immunohistochemical staining of normal human epidermis showed that calpain I was localized in the cytoplasm of keratinocytes in the mid to upper epidermis but not in the basal cells. In untreated psoriatic epidermis, the deposition of this proteinase was visualized weakly just beneath the stratum corneum. However, remarkable staining was observed after photochemotherapy of topical psoralen plus long-wave UV irradiation. Whether the photochemotherapy induced a quantitative increase in the amount of calpain or merely made calpain more stainable by altering the membrane remains unknown.