Secondary structure of the particle associating domain of apolipoprotein B-100 in low-density lipoprotein by attenuated total reflection infrared spectroscopy.
The secondary structure of the human low-density lipoprotein (LDL) apo B-100 fragment embedded in the lipid domain of the particle has been investigated by Fourier transform attenuated total reflection infrared spectroscopy (FTIR-ATR). The solvent-exposed region of the protein was hydrolyzed by using different proteases (alpha-chymotrypsin, trypsin, proteinase K) for incubation times varying between 24 min and 48 h. Analysis of the FTIR-ATR spectra after repurification of the digested LDL particle indicates the same trend for all the hydrolysis conditions tested: the peptides remaining associated with the particle are rich in beta-sheet structure. Dichroism spectra reveal that at least part of the beta-sheets is associated with the phospholipid component of the particle.
Laboratoire de Chimie Physique des Macromolécules aux Interfaces, Université Libre de Bruxelles, Belgium.
E
E
Goormaghtigh
V
V
Cabiaux
J
J
De Meutter
M
M
Rosseneu
J M
JM
Ruysschaert
D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000737:chemistry*; D002918:Chymotrypsin; D019286:Endopeptidase K; D006801:Humans; D008077:Lipoproteins, LDL / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012697:Serine Endopeptidases; D013055:Spectrophotometry, Infrared / Q000379:methods; D014357:Trypsin
D053299:Apolipoprotein B-100; D001055:Apolipoproteins B; D008077:Lipoproteins, LDL; D012697:Serine Endopeptidases; D002918:Chymotrypsin; D014357:Trypsin; D019286:Endopeptidase K