Biosynthesis of sucrase-isomaltase in the small intestine hereditarily deficient in sucrase activity

对蔗糖的不耐受是由于缺乏与小肠刷状缘膜相关的蔗糖酶-异麦芽糖酶引起的。我们发现在某些品系的家麝鼩，臭鼩（Suncus murinus）遗传性蔗糖酶缺乏症。在本工作中，我们的目的是免疫化学阐明（蔗糖酶）异麦芽糖酶的生物合成的细胞内途径，在sucrase活性的遗传性缺陷的Suncus肠。首先，我们已经纯化正常的蔗糖酶异麦芽糖酶和异常的无蔗糖酶的异麦芽糖酶从正常和突变indibibibrium，分别，并研究其性质。蔗糖酶和异麦芽糖酶分别为116和96 kDa。该复合物的麦芽糖酶活性主要来自蔗糖酶。第二，我们制备了抗纯化的正常复合物的抗体。试管定量沉淀结果表明，正常蔗糖酶-异麦芽糖酶和不含蔗糖酶的异麦芽糖酶位于同一微绒毛中，即它们在同一细胞中合成并转运至刷状缘膜。与膜相关的酶，无论是正常的还是突变的，都会与抗体发生部分反应，这给诸如本发明的免疫形态学方法带来了严重的问题。

Intolerance to sucrose is caused by lack of sucrase-isomaltase associated with the brush border membrane of the small intestine. We have found hereditary sucrase deficiency in some strains of the house musk shrew, Suncus murinus. In the present work we aimed at immunochemically elucidating the intracellular pathway of biosynthesis of (sucrase-) isomaltase in the Suncus intestine hereditarity deficient in sucrase activity.First, we have purified normal sucrase-isomaltase and abnormal sucrase-free isomaltase from normal and mutant indibiduals, respectively, and investigated their properties. Sucrase and isomaltase was of 116 and 96 kDa, respectively. The maltase activity of the complex was mainly ascribed to sucrase.Second, we prepared antibodies against the purified normal complex in a rabbit. The results of quantitative precipitation in test tube showed that normal sucrase-isomaltase and sucrase-free isomaltase were located in the same microvillus ; that is, they were synthesized and transported to the brush border membrane in the same cell. The enzymes associated with the membrane, normal or mutant, partially reacted with the antibodies, posing a serious problem to immunomorphological approaches such as the present one.