Homogenates made from the mucosa of the guinea pig small intestine were fractionated in a zonal rotor by rate and isopyenic centrifugation in sucrose gradients. Density perturbation of endoplasmic reticulum vesicles was done by treating homogenate with pyrophosphate and was analysed by isopyenic centrifugation. Subcellular fractions were analysed for the distribution of markers for brush borders, basolateral plasma membrane, lysosomes, peroxisomes, mitochondria, nuclei and endoplasmic reticulum. Fractions were also analysed for the distribution of propionyl-, butyryl-, and palmityl-CoA synthetases. For carnitine acetyl and palmityl transferases, and for phosphatidate phosphatase. Comparison of marker and unknown distributions shows that palmityl-CoA synthetase is located on the endoplasmic reticulum, while propionyl- and butyryl-CoA synthetases and carnitine acetyl and palmityl transferase are exclusively mitochondrial. Phosphatidate phosphatase has complex subcellular localisation with activity in brush borders, microsomes (possibly not the endoplasmic reticulum component) and possibly lysosomes.
|Number of pages
|European Journal of Cell Biology
|Published - 1979