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Single molecular observation of the apolipoprotein B and its folding intermediates in reassembled low density lipoprotein
Author(s) -
Chang ChiaChing,
Chu HsuehLiang,
Cheng TsaiMu
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.684.2
Subject(s) - apolipoprotein b , chemistry , lipoprotein , folding (dsp implementation) , ldl receptor , mutant , ultracentrifuge , biochemistry , cholesterol , receptor , gene , electrical engineering , engineering
Low density lipoprotein‐cholesterol (LDL‐C) is a clinical significant marker of cardiovascular disease risk. Each particle of LDL contains only one molecule of apolipoprotein B (apoB). In human, the liver secretes full‐length apoB (apoB‐100) which also serves as a ligand for receptor‐mediated uptake of LDL by a variety of cell types. The deficiency of the LDL assembly may play a vital role in many diseases progression. Therefore, it is desired to reveal the folding/assembly process of ApoB. However, it is challenge to monitor its folding/assembly intermediates due to its high insolubility in an aqueous solution. In this study, we had purified LDL from human plasma by sequential ultracentrifugation and the apoB‐100 had been isolated from LDL by ice cheer method. ApoB was dissolved in the denature buffer which contained detergents. The apoB‐100 protein was refolded by the way of an over‐critical refolding process. The folding intermediates of apoB‐100 and its truncated mutants could be observed by immunofluorescence microscopy analysis at the single molecular level. Our data indicate that the N terminus of apoB is important for LDL assembly and stabilization. This study can help the understating the mechanism of lipoproteins folding. Meanwhile, the transportation of LDL in the living body can be monitored, too.