RELATION BETWEEN NUMBER OF APOLIPOPROTEIN(A) KRINGLE-4 REPEATS AND MOBILITY OF ISOFORMS IN AGAROSE-GEL - BASIS FOR A STANDARDIZED ISOFORM NOMENCLATURE

The size of apolipoprotein(a) [apo(a)] varies from 187 to 648 kDa beca use of interallelic differences in the number of kringle 4-encoding se quences in the apo(a) gene. Plasma apo(a) isoform sizes were determine d by a high-resolution sodium dodecyl sulfate-agarose gel electrophore tic method, followed by immunoblotting. The relation between the numbe r of apo(a) kringle 4-encoding sequences in the apo(a) gene, as assess ed by pulsed-field gel electrophoresis and genomic blotting, and the m obility of apo(a) isoforms in agarose gel was evaluated in 29 individu als who had 48 expressed apo(a) isoforms that contained between 12 and 41 kringle 4 repeats. The log of the kringle number was linearly rela ted to the distance the isoform migrated on the agarose gel (r = 0.999 ). A nomenclature is proposed to designate apo(a) isoforms by the resp ective number of kringle 4 repeats.