Vitamin D-binding protein synthesized by a human hepatocellular carcinoma cell line.
The binding protein for 25-hydroxycholecalciferol was studied in the medium spent for the culture of HuH-7 cells, which were originally derived from a human hepatocellular carcinoma tissue. The binding protein for 25-hydroxycholecalciferol synthesized by HuH-7 cells was immunologically similar to vitamin D-binding protein in human serum and had an inter-alpha mobility. A sedimentation coefficient of 4.1 S was found on sucrose density gradient analyses. The molecular weight was estimated to be approximately 58,000 by gel filtration on a standardized column of Sephadex G-150. When mixed with filamentous actin purified from rabbit skeletal muscle, it depolymerized filamentous actin and bound to monomeric, globular actin to make a 5.5 S 1:1 molar complex with a molecular weight of approximately 100,000. These results support the conclusion that HuH-7 cells produce a functional vitamin D-binding protein.
D002112:Calcifediol / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D002850:Chromatography, Gel; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism*; D011485:Protein Binding; D014809:Vitamin D-Binding Protein / Q000096:biosynthesis*
D014809:Vitamin D-Binding Protein; D002112:Calcifediol