A NOVEL METHOD FOR THE PURIFICATION OF SELENOPROTEIN-P FROM HUMAN PLASMA

Selenoprotein P was purified from human plasma using conventional chro matographic methods featuring metal-chelate-affinity chromatography as the final step. Two distinct isoforms with different selenium content were isolated and identified by N-terminal sequencing and immunoblot analysis. Their molecular mass is 61 and 51 kDa, respectively. Both is oforms could be detected in fresh plasma from five individuals. This r ules out the possibility of the second isoform being an artifact which results from degradation of full-length selenoprotein P during purifi cation. (C) 1998 Academic Press.