Isolation and carbohydrate composition of glycopeptides of human apo low-density lipoprotein from normal and type II hyperlipoproteinemic subjects.
Glycopeptides were prepared from the delipidized protein of low-density lipoprotein (LDL, d=1.019-1.063) of three normal and three familial heterozygous type II hyperlipoproteinemic (HLP) subjects. The glycopeptides of all subjects were resolved into three groups by gel filtration on Bio-Gel P6 following papain (EC 3.4.22.2) digestion and initial purification on Bio-Gel P2. In normal individuals the component of largest molecular weight (F-1) contained mannose (Man), N-acetyl glucosamine (GlcNAc) galactose (Gal), and N-acetyl neuraminic acid (NANA) in the respective amounts of 45.9 +/- 6.7, 37.3 +/- 5.9, 28.6 +/- 3.4, and 27.0 +/- 3.9 nmol/mg original apoprotein. The group of smallest molecular weight (F-3) contained essentially only Man (25.8 +/- 1.5 nmol/mg protein) and GlcNac (3.0 +/- 0.4 nmol/mg protein) with traces of Gal and NANA. A group of intermediate molecular weight (F-2) exhibited considerable heterogeneity and contained Man, GlcNAc, Gal, and NANA in the amounts of 45.9 +/- 5.1, 18.3 +/- 1.7, 11.0 %/- 1.7, and 7.7 %/- 1.2 nmol/mg protein. While the major portion of NANA (78%), Gal (71%), and GlcNAc (64%) was present in F-1, approximately 22% of the total Man was in F-3. No major differences were detected in the carbohydrate composition of the three glycopeptide fractions of LDL apoptotein from normal and Type II subjects.
D000117:Acetylglucosamine / Q000032:analysis; D002791:Cholesterol, Dietary; D005260:Female; D005690:Galactose / Q000032:analysis; D006020:Glycopeptides / Q000097:blood / Q000302:isolation & purification; D006579:Heterozygote; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood* / Q000235:genetics; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008358:Mannose / Q000032:analysis; D012794:Sialic Acids / Q000032:analysis
D002791:Cholesterol, Dietary; D006020:Glycopeptides; D008077:Lipoproteins, LDL; D012794:Sialic Acids; D008358:Mannose; D000117:Acetylglucosamine; D005690:Galactose