Lutton C, Zilversmit D B
Lipids. 1976 Jan;11(1):16-20. doi: 10.1007/BF02532579.
The 105,000 g supernatant and pH 5.1 supernatant fractions from rat intestinal homogenates stimulate phosphatidylcholine exchange between [32P] phosphatidylcholine liposomes and beef heart mitochondria. This active fraction shows the characteristics of a protein. Isoelectric focusing of the intestinal pH 5.1 fraction shows two peaks of phosphatidylcholine exchange activity: one at an acidic pH (4.5-5.3), the other in a basic pH range (8-9). The second peak of activity appears to be a new phospholipid exchange protein. The anatomic distribution of phosphatidylcholine exchange activity in intestine has been investigated. Expressed per mg of protein, phosphatidylcholine exchange activity is higher in mucosa than in the intestinal wall. No significant differences have been found between villi and crypts cells or between jejunal and ileal villi. Futhermore, exchange activity per mg of protein in mucosa is unaffected by fasting or by feeding a high fat or high cholesterol diet. This suggests that phospholipid exchange activity in the absorptive cells is not a rate limiting step in the process of fat absorption.
大鼠肠道匀浆的105,000g上清液和pH 5.1上清液组分可刺激[32P]磷脂酰胆碱脂质体与牛心线粒体之间的磷脂酰胆碱交换。该活性组分表现出蛋白质的特性。对肠道pH 5.1组分进行等电聚焦，显示出磷脂酰胆碱交换活性的两个峰：一个在酸性pH值（4.5 - 5.3），另一个在碱性pH范围（8 - 9）。第二个活性峰似乎是一种新的磷脂交换蛋白。已对肠道中磷脂酰胆碱交换活性的解剖分布进行了研究。以每毫克蛋白质计算，黏膜中的磷脂酰胆碱交换活性高于肠壁。绒毛细胞与隐窝细胞之间或空肠绒毛与回肠绒毛之间未发现显著差异。此外，黏膜中每毫克蛋白质的交换活性不受禁食或喂食高脂肪或高胆固醇饮食的影响。这表明吸收细胞中的磷脂交换活性不是脂肪吸收过程中的限速步骤。
