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标题：The Role of Membrane-Associated Irom-Binding Complex in Intestinal Irom Absorption in the Rat
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作者：Hideo ORIMO ; Sanae HISAYASU ; Yukihiko HIRAI 等
期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1994
卷号：40
期号：6
页码：511-522
DOI：10.3177/jnsv.40.511
出版社：Center for Academic Publications Japan
摘要：A membrane-associated iron-binding complex was isolated from rat intestinal mucosa during iron absorption. Two ⁵⁹Fe peaks (peaks 1 and 2) were separated on Sepharose 6B gel filtration from detergent solubilized 20, 000 × g precipitate of upper intestinal mucosal homogenate after administration of ⁵⁹Fe-labelled ferrous materials. Peak 1 was a membrane iron-binding complex whose apparent molecular weight was over 10⁶ Da estimated by gel filtration, while peak 2 was identified as ferritin. Three major bands were detected on SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of peak 1. The treatment of mucosal homogenate with 5mM ethylenediaminetetraacetic acid released ⁵⁹Fe binding from peak 1. Incorporation of ⁵⁹Fe to peak 1 showed the maximum at 1 h and then reduced, while [⁵⁹Fe] ferritin showed reciprocal behavior, which suggested that peak 1 may be a rapid turnover iron pool and transfer ⁵⁹Fe to ferritin. Peak 1 was also isolated from the brush border membrane and showed similar SDS-PAGE pattern to that from the 20, 000 × g precipitate of mucosal homogenate. Western blot analysis did not reveal immunoreactive transferrin in peak 1. Those findings suggest that peak 1 may be a non-ferritin, non-transferrin iron-binding complex located on the brush border membrane and accept iron from the intestinal canal during iron absorption.
关键词：iron-binding complex;brush border membrane;iron absorption;transferrin;ferritin;rat