The interaction of heparin with an apoprotein of human very low density lipoprotein.
An arginine-rich apoprotein obtained from human triglyceride-rich lipoprotein was isolated on a heparin affinity column when either the aqueousor urea-soluble apoproteins were applied to the column. Of all the aqueous- or urea-soluble apoproteins, only this arginine-rich protein exhibited a binding affinity to heparin. This protein was eluted from the column at sodium chloride concentrations above 0.35 M in the absence of urea and between 0.17-0.2 M when isolated in urea. The protein has been characterized by amino acid analysis, immunoelectrophoresis, dodecyl sulfate polyacrylamide electrophoresis, isoelectric focusing, and NH(2)-terminal analysis. It has the same amino acid composition, NH(2)-terminal, and molecular weight as previously described for human arginine-rich apoprotein. The triglyceride-rich lipoproteins of fasting normal humans were eluted as two fractions when applied to the heparin affinity column. A small amount was eluted in the unbound fraction and this species contained virtually no arginine-rich apoprotein. The bulk of the triglyceride-rich lipoproteins eluted in the bound fraction and contained appreciable amounts of arginine-rich apoprotein. The bound lipoproteins had more cholesterol and cholesterol ester and less triglyceride than the unbound. The isolated arginine-rich apoprotein was derivatized with phenylglyoxal with a resulting alteration of 75% of the arginine residues. This modified apoprotein did not bind to the heparin affinity column. Similar treatment of the whole triglyceride-rich lipoprotein produced a lipoprotein that was totally eluted in the unbound fraction.
D000596:Amino Acids / Q000032:analysis; D001053:Apolipoproteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D001120:Arginine / Q000378:metabolism; D002846:Chromatography, Affinity; D005215:Fasting; D006493:Heparin / Q000378:metabolism*; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood; D008055:Lipids / Q000032:analysis; D008079:Lipoproteins, VLDL / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D011485:Protein Binding; D014280:Triglycerides / Q000097:blood
D000596:Amino Acids; D001053:Apolipoproteins; D008055:Lipids; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D006493:Heparin; D001120:Arginine