Apolipoprotein B-100 is the major form of this apolipoprotein secreted by human intestinal Caco-2 cells.
Although the discovery of stop codon has explained the mechanism for the formation of the intestinal marker, apolipoprotein B-48, the dispute regarding the presence of apolipoprotein B-100 in the intestine is still unsettled. To further investigate the characteristics of intestinal apolipoprotein B, the newly developed human colonic adenocarcinoma Caco-2 cells which express functional properties of the differentiated enterocytes, were used. SDS-polyacrylamide gel electrophoresis analyses of the intact culture medium or its lipoproteins of d less than 1.23 g/ml showed the presence of only a single protein band of apolipoprotein B-100 with no detectable apolipoprotein B-48. After immunoblotting with oligoclonal antibodies to the amino-terminal peptide of apolipoprotein B, a trace amount of apolipoprotein B-48 was observed in the isolated lipoproteins, but not in the intact culture medium. These results suggest that apolipoprotein B-100 is the major form of apolipoprotein B secreted by human intestinal cells.
Lee
D M
DM
Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City 73104.
Dashti
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N
Mok
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D000230:Adenocarcinoma; D000596:Amino Acids / Q000032:analysis; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D003110:Colonic Neoplasms; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D015151:Immunoblotting
D000596:Amino Acids; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B