Toyoshima M, Gräsbeck R
Scand J Clin Lab Invest. 1987 May;47(3):277-84.
The distribution of cobalamin derivatives in porcine enterocytes was studied using thin-layer chromatography and bioautography. Compared with the original homogenate, adenosyl-cobalamin (Ado-Cbl) was concentrated 5-10 times in the mitochondrial fraction. Cyanocobalamin was found in the lysosomal fraction, but was not detected in the mitochondria. Methyl-cobalamin (Me-Cbl) was found only in the sap fraction and could not be detected in the total homogenate. Hydroxocobalamin was the main form of Cbl in the lysosomal fraction. These results provide indirect evidence that in enterocytes methylmalonyl-CoA mutase, the coenzyme of which is Ado-Cbl, is located in the mitochondrial fraction and that methionine synthetase, the coenzyme of which is Me-Cbl, is located in the sap fraction. These enzymes thus appear to be distributed in the same way as in liver cells.
采用薄层色谱法和生物自显影法研究了钴胺素衍生物在猪肠上皮细胞中的分布。与原始匀浆相比，腺苷钴胺素（Ado-Cbl）在线粒体部分浓缩了5至10倍。氰钴胺素存在于溶酶体部分，但在线粒体中未检测到。甲基钴胺素（Me-Cbl）仅存在于细胞液部分，在总匀浆中未检测到。羟钴胺素是溶酶体部分钴胺素的主要形式。这些结果提供了间接证据，表明在肠上皮细胞中，以Ado-Cbl为辅酶的甲基丙二酰辅酶A变位酶位于线粒体部分，而以Me-Cbl为辅酶的甲硫氨酸合成酶位于细胞液部分。因此，这些酶的分布方式似乎与肝细胞相同。
