期刊名称：Journal of Clinical Biochemistry and Nutrition
印刷版ISSN：0912-0009
电子版ISSN：1880-5086
出版年度：1989
卷号：7
期号：1
页码：43-51
DOI：10.3164/jcbn.7.43
出版社：The Society for Free Radical Research Japan
摘要：The content of cobalamin-binding protein (Cb1BP) was measured in stomach extracts and various cell lines. Cb1BP was increased in the cancer extract compared with non-cancerous control. The level of Cb1BP was also increased in serum-free culture medium of a gastric cancer cell line, but was almost undetectable in media of control cell lines. This output of Cb1BP in medium was suppressed by cycloheximide. These Cb1BPs were immunologically cross-reactive with anti saliva R binder antibody. The M r, determined by immunoprecipitation, was 70kDa and the pI, 2.8-3.2. From these properties, this Cb1BP in cancer cells was considered to be an isoprotein of the cobalamin R binder. Histochemical studies showed that immunoreactive Cb1BP was confined to cytosol of cancer cells and cells in metaplasia. The present results suggest that Cb1BP of the R binder type is synthesized de novo in some type of gastric cancer cells and in metaplastic cells.
