抄録
Plasma apo E levels are increased in type III hyperlipoproteinemia. Plasma apo E has been shown to have isoprotein forms, and it was re cently suggested that a deficiency of apo E-III isoprotein is associated with type III hyperlipoproteinemia.
To understand better apo E metabolism, we studied plasma apo E isoproteins using high resolution, two-dimensional polyacrylamide gel electrophoresis. Apo VLDL obtained from 10 normal subjects and 2 patients with type III hyperlipoproteinemia were analysed.
1 The patterns of VLDL apo E isoproteins from different normal subjects were of two major types, designated class α and class β according to Zannis et al. Class α consists of two major isoproteins, while class β consists of one major isoprotein.
2 Mixing experiments of apo VLDL obtained from different normal subjects with an α or a β pattern revealed that the α or β patterns were not always superimposable. It seemed that class α or class β is subdivided into several subclasses.
3 Two patients with type III hyperlipoproteinemia had a β pattern of VLDL apo E without any missing apo E isoproteins.
4 Mixing experiments of apo VLDL obtained from normal subject and patient with type III hyperlipoproteinemia indicated that the entire pattern of apo E isoproteins in patients with type III hyperlipoproteinemia was shifted to more acidic isoelectric points. This unique subclass of apo E isoproteins is seemed to be β IV pattern according to Zannis et al.
