Biochemistry 1990, 29, 59 19-5924
5919
Lipoprotein(a) Binding to Other Apolipoprotein B Containing Lipoproteinsf Vuong N . Trieu and Walter J. McConathy* Lipoprotein and Atherosclerosis Research Program, Oklahoma Medical Research Foundation, 825 N.E. 13th Street, Oklahoma City, Oklahoma 73104 Received January 10, 1990; Revised Manuscript Received March 29, 1990
A method combining ligand dot blotting and digital imaging was used to determine the apparent dissociation constant (KD)for the binding of lipoprotein(a) to low-density lipoproteins2 (Lp(a)-LDL,). By use of this approach, the KD for the Lp(a)-LDL, complex was shown to be in the nanomolar range [(1.05 M, n = 41. The Lp(a)-LDL, interaction was both hydrophobic and ionic; however, f 0.21) X hydrophobic forces predominated because the interaction was demonstrable a t high salt concentration (>2 M NaCl), while no complex was detectable a t low salt concentration (
