[Apoproteins in dyslipoproteinemia (author's transl)]

Abstract

Plasma lipids (cholesterol, triglycerides) which are essentially hydrophobic components circulate as lipid-protein complexes. Lipoproteins are defined by their protein moiety (apoprotein) whose composition corresponds to their density class. Low density lipoproteins are characterized by apoprotein B; in contrast, apoproteins A are found in high density lipoproteins. Apoproteins, consisting of a single or several polypeptide chains, play an essential role not only as structural entities but also as functional units in relation to the enzymes of lipoprotein metabolism. It is therefore possible that apoproteins may occupy a major place in the physiopathology of dyslipoproteinemias. To date, their roles have been established in atherosclerosis and some hyperlipoproteinemias with hypertriglyceridemia. Future studies of apoproteins may give a better understanding of certain other poorly defined metabolic disorders. At present, some of the hyperlipoproteinemias have been characterized by variations of one or several apoprotein levels. Nevertheless, the interpretation of this data must be cautious in view of a number of unknown factors.