Polypeptide composition of rat high density lipoprotein: Characterization by SDS-gel electrophoresis

Electrophoresis on sodium dodecylsulfate-containing polyacrylamide gels of high density lipoprotein obtained from plasma of sucrose-fed rats reveals a complex pattern of three major bands and several minor, low molecular weight bands. The component present in the greatest amount is a 27,000 molecular weight protein which has aspartic acid or asparagine as N-terminus and alanine as C-terminus, and which is considered comparable to the A-I protein of human high density lipoprotein. The other major rat polypeptides have molecular weights of 46,000 (A-IV) and 35,000 (“arginine-rich”). The “arginine-rich” protein may be identical to a major polypeptide component of rat very low density lipoprotein.