Abstract: Methods for the expression of kringle domains of apoliprotein(a) are described. The domains, including kringle 4 domains and the unique kringle 5 domain, are efficiently expressed as fusion proteins from transformed Escherichia coli host cells. The fusion polypeptides may be employed directly to generate antibodies to human lipoprotein (a) or cleaved to provide the pure kringle polypeptide. Monoclonal antibodies to the kringle 4 domains and to kringle 5 domain may be employed to assay levels of human apolipoprotein (a) in blood as a measure of risk of coronary heart disease.

Abstract: The present invention relates to a method for the detection and quantification of lipoprotein(a) present in a fluid sample which method is not sensitive to the presence of plasminogen and which comprises contacting the fluid sample with anti-apo(a) antibody and forming a first immobilized complex of lipoprotein(a)/anti-apo(a) first antibody, contacting said first complex with anti-apo B second antibody and thereafter quantitating Lp(a) based on the amount of bound anti-apo B antibody. Immobilized rabbit anti-human apo(a) antibody can be employed as the first, capture, antibody and goat-anti-human apo B antibody as the second antibody. The amount of anti-apo B antibody bound is quantitated through binding of a third antibody/enzyme conjugate, e.g., a rabbit anti-goat antibody/alkaline phosphatase conjugate, followed by reaction with a suitable enzyme substrate such as paranitrophenyl phosphate.