Apolipoprotein(a) isoform size influences binding of lipoprotein(a) to plasmin-modified des-AA-fibrinogen

High lipoprotein(a) levels and small apolipoprotein(a) sizes are associated with endothelial dysfunction in a multiethnic cohort

“…Thus, in addition to its effect on Lp(a) level, apo(a) itself appears to exert direct effects on atherogenesis. Although small apo(a) sizes have previously been shown to enhance prothrombotic potential of Lp(a) (24,25), our study substantiates in vivo that apo(a) size variation may confer atherogenic properties (26). Further studies are needed to delineate the precise mechanism by which apo(a) size heterogeneity predispose to atherosclerosis.…”

Evidence that the fibrinogen binding domain of Apo(a) is outside the lysine binding site of kringle IV-10: a study involving naturally occurring lysine binding defective lipoprotein(a) phenotypes.

“…This suggestion receives additional support from our current results on free apo(a) and those on apo(a) recombinant by Harpel et al (22) indicating that kringle IV-2 is not involved in the fibrinogen binding, since this process is not significantly influenced by the size of apo(a), which depends on the number of kringle IV-2. Other investigators studying the whole Lp(a) particle have reported an effect of apo(a) size on fibrin(ogen) binding (18,23,24). We cannot reconcile these results except for invoking differences in the apo(a) phenotypes studied and assay conditions.…”

Polymorphisms in the Apolipoprotein(a) Gene, Plasma Lp(a) and Cardiovascular Risk

“…This finding was not confirmed by others [26,73]. Previous studies showed that the length of apo(a) influences binding of Lp(a) particles to fibrin [74][75][76]. Simo et al [77] have also found a correlation between Lp(a) lysine-binding activity and the KIV number in the single-banded phenotypes of CAD patients.…”