Phospholipid composition and acyltransferase activity of lamellar bodies isolated from rat lung.
Phospholipid composition and acyltransferase activity of lamellar bodies isolated from rat lung.
复制标题
从大鼠肺中分离的层状体的磷脂组成和酰基转移酶活性。
DOI：
10.1016/0003-9861(76)90295-2
复制
发表时间：
1976
影响因子：
3.9
通讯作者：
W. Longmore
中科院分区：
文献类型：
--
作者：
M. Engle;R. Sanders;W. Longmore
The role of the lamellar body of the type II pneumocyte in the synthesis and storage of the phospholipids of the surfactant lipoprotein lining the alveolar surface has been investigated. Electron microscopy has been used to establish the purity of the isolated lamellar body, microsomal, and mitochondrial fractions. Additional proof of lamellar body purity was obtained by enzyme marker studies. The phospholipid:protein ratio of each of the above fractions was determined as well as that of surfactant lipoprotein isolated from rat lung. Lamellar body phospholipid:protein ratio was highest, 3.7 μmol of lipid phosphorus/mg of lung protein. The phospholipid composition of the lamellar body fraction was found to be similar to that of the isolated surfactant lipoprotein. Lamellar body phosphatidylcholine and phosphatidylglycerol each contained over 90% saturated fatty acids. The lamellar body fraction was found to possess significant acyltransferase activity between [1-14C]palmitoyl-CoA and phosphatidylcholine. This activity was somewhat higher than in the microsomal fraction and much greater than in the mitochondrial fraction. The activity in all fractions was stimulated by Ca2+and Mg2+. [1-14C]oleoyl-CoA did not serve as an effective acyl donor. When 1-palmitoyl-2-lysophosphatidylcholine was used as the acceptor molecule and [1-14C]palmitoyl-CoA the donor, acyltransferase activity was increased over that found with phosphatidylcholine as donor in all fractions. The microsomal fraction had the greatest activity and the lamellar body fraction the least. The data obtained support the hypothesis that the lamellar body is involved in the synthesis and storage of the phospholipids of the surfactant lipoprotein complex.
