Lipoprotein(a): identification of subjects with a superbinding capacity for fibrinogen.
We have previously shown that the binding of lipoprotein(a) [Lp(a)] to immobilized fibrinogen involves the domain located in kringles IV-5 to IV-8, but not kringle IV-10. In extending those studies to subjects living in Chicago and in the island of Sardinia, we found that about 6% of them had an Lp(a) with Bmax values of 27.7+/-6.0 fmol, which were about 5-8-fold higher than those of controls (3.4+/-2.8 fmol) and in the range of those observed for free apo(a) derived from the Lp(a) of controls (36.6+/-2.9 fmol). This superbinding phenotype was unaffected by age, sex, type of lipid disorder and hypolipidemic agents, and also had a familial incidence. We are currently exploring the hypothesis that this fibrinogen superbinding phenotype is due to conformational changes of apolipoprotein(a) [apo(a)] resulting from the lipid content and composition of the Lp(a) particle and/or sequence anomalies in the kringle domain IV-5 to IV-8.
Scanu
A M
AM
Department of Medicine, University of Chicago, IL 60637, USA.
Atzeni
M M
MM
Edelstein
C
C
Tonolo
G
G
Maioli
M
M
Klezovitch
O
O
D000367:Age Factors; D000368:Aged; D001054:Apolipoproteins A / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D007558:Italy; D018082:Kringles / Q000235:genetics; D017270:Lipoprotein(a) / Q000235:genetics / Q000502:physiology*; D008239:Lysine / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D010375:Pedigree; D010446:Peptide Fragments / Q000378:metabolism; D010641:Phenotype; D011485:Protein Binding / Q000235:genetics; D011487:Protein Conformation; D012737:Sex Factors
D001054:Apolipoproteins A; D017270:Lipoprotein(a); D010446:Peptide Fragments; D005340:Fibrinogen; D008239:Lysine