Induction of rat alkaline phosphatase isozymes bearing a glycan-phosphatidylinositol anchor modified by in vivo treatment with a benzimidazole derivative linked to ethylbenzene
Induction of rat alkaline phosphatase isozymes bearing a glycan-phosphatidylinositol anchor modified by in vivo treatment with a benzimidazole derivative linked to ethylbenzene
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DOI：
10.1016/s0305-0491(00)00252-2
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发表时间：
2000-10-01
影响因子：
2.2
通讯作者：
Komoda, T
中科院分区：
文献类型：
--
作者：
Harada, T;Koyama, I;Komoda, T
血清碱性磷酸酶（ALP）以可溶性形式检出，这是通过糖基-磷脂酰肌醇部分（GPI锚）处的切割从膜位点易位的结果。已知在某些病理和生理条件下可在血清中检测到膜结合ALP（mALP），并且其可通过磷脂酰肌醇特异性磷脂酶C（PIPLC）、磷脂酶D、胆汁盐、去污剂等在体外增溶为可溶性ALP（sALP）。我们观察到通过管饲给予苯并咪唑衍生物的大鼠血清中ALP活性显著增加，在圆盘PAGE上检测到慢迁移的ALP（SM-ALP），其类似于mALP，但对PIPLC和正丁醇处理具有抗性。另一方面，无花果蛋白酶处理使SM-ALP移位到sALP位置。十二烷基硫酸钠-聚丙烯酰胺平板凝胶电泳（SDS-PAGE）显示SM-ALP的分子大小小于sALP，免疫反应性为肠型。十二指肠和空肠中也检测到SM-ALP。SM-ALP的糖链结构主要为双触角复合型，与小肠sALP糖链结构一致。这些结果表明，由苯并咪唑衍生物诱导的肠ALP在其C-末端或GPI锚区被修饰，并且该区域的修饰也可能参与易位到血流中。(C)2000 Elsevier Science Inc. All rights reserved.
Serum alkaline phosphatase (ALP) is detected in soluble-form as a result of translocation from the membrane site by cleavage at the glycosyl-phosphatidylinositol moiety (GPI anchor). It is known that membrane-bound ALP (mALP) can be detected in serum in certain pathological and physiological conditions, and that it can be solubilized in vitro to soluble-ALP (sALP) by phosphatidylinositol-specific phospholipase C (PIPLC), phospholipase D, bile salt, detergent, etc. We observed a marked increase in ALP activity in the serum of rats given a benzimidazole derivative by gavage, and detected it as slow-migrating ALPs (SM-ALPs), which were mALP-like but resistant to PIPLC and n-butanol treatment on disc PAGE. On the other hand, ficin treatment made SM-ALPs shift to the sALP position. The molecular size of the SM-ALPs was smaller than that of sALP on sodium dodecyl sulphide-polyacrylamide slab-gel electrophoresis (SDS-PAGE), and immunoreactivity revealed the intestinal type. SM-ALPs were also detected in the duodenum and jejunum. The main sugar chain structure of SM-ALPs was the biantennary complex-type, which was coincided with intestinal sALP sugar chain. These results suggest that intestinal ALPs induced by the benzimidazole derivative were modified in their C-terminus or GPI anchor region and modification of this region may also participate in translocation into the bloodstream. (C) 2000 Elsevier Science Inc. All rights reserved.