Carboxyl-terminal truncation of apolipoproteinB-100 inhibits lipoprotein(a) particle formation.
Recombinant expression systems for both apo(a) and apoB were used to identify sequences in apoB which are required for Lp(a) formation. Incubation of a [35S]Cys-labelled 17-kringle form of apo(a) with supernatants from rat hepatoma (McA-RH7777) cells expressing apoB-88, apoB-94 and apoB-100 resulted in covalent r-Lp(a) formation only with apoB-100. Additionally, apoB-86 present in the LDL of a hypobetalipoproteinemic subject did not associate with a 12-kringle form of recombinant apo(a) to form r-Lp(a) complexes. Our data suggest that sequences within the C-terminal 6% of apoB-100 are essential for Lp(a) assembly.
Gabel
B
B
Department of Biochemistry, Queen's University, Kingston, Ont., Canada.
Yao
Z
Z
McLeod
R S
RS
Young
S G
SG
Koschinsky
M L
ML
D000818:Animals; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000737:chemistry* / Q000235:genetics; D002264:Carboxylic Acids / Q000737:chemistry; D002478:Cells, Cultured; D006801:Humans; D018082:Kringles; D017270:Lipoprotein(a) / Q000096:biosynthesis*; D051381:Rats; D011994:Recombinant Proteins; D017384:Sequence Deletion; D014407:Tumor Cells, Cultured
D053299:Apolipoprotein B-100; D001055:Apolipoproteins B; D002264:Carboxylic Acids; D017270:Lipoprotein(a); D011994:Recombinant Proteins