Apoprotein S, a family of human serum lipoprotein polypeptides

Glucose infusions given to neurological and postsurgical patients in the absence of oral feeding were found to increase the amount of new polypeptides in high density lipoproteins from 3 to 40% of total proteins as compared to 0.1% in normal subjects fed a regular diet. This increase was observed in HDL2 as well as in HDL3 and even in VLDL. Eight polymorphic forms were detected by chromatography, polyacrylamide gel electrophoresis and isoelectric focusing. The partial amino acid sequence of one of these forms is given: the first 26 NH2-terminal residues are identical to the amphipathic helical segment of SAA protein, theoretically responsible for the lipid binding. The role of glucose as the major factor involved in the production of these apoproteins is discussed.