The objective of this research is to study certain aspects of the chemistry of human serum lipoproteins. Lipoproteins will be isolated by ultracentrifugal, electrophoretic, and chromatographic procedures. The purified lipoproteins and apoproteins will be characterized by sedimentation, electrophoresis, titration, and by a variety of spectrophotometric, immunochemical, and immunologic methods. The result of this work should provide understanding of certain aspects of lipoprotein structure and this, in turn, will be required for eventual understanding of the mechanism of lipid transport and of pathogenesis of atherosclerotic heart disease.