Figure 7.

Analytical fractionation by isopycnic density gradient centrifugation of LDM (a) and the parent microsomes (b) from which they were derived. Shown are the densities of each fraction, the protein distribution, the distribution of the Golgi markers β1, 4 galactosyl transferase (GT, measured by enzyme assay) and the marker mannosidase II (Man II, measured by immunoblot analysis). The distribution of p97 and syntaxin 5 isoforms are indicated as are the distributions of the primarily cis Golgi-located protein α₂p24 and the primarily ER-located protein calnexin. The median density of the constituents are indicated on the right next to the molecular masses of the respective proteins.