title: Sulfhydryl-selective fluorescence labeling of lipoprotein(a) reveals evidence for one single disulfide linkage between apoproteins(a) and B-100.
abstract: Human lipoprotein(a) and low-density lipoprotein were labeled with two different sulfhydryl-selective fluorescence markers. The hydrophilic fluorophore lucifer yellow iodoacetamide and the apolar compound 6-acryloyl-2-(dimethylamino)naphthalene were used to derivatize free -SH groups in the lipoproteins. Three sulfhydryls could be detected in low-density lipoprotein, whereas only two cysteines were available in lipoprotein(a). One of the three -SH groups in low-density lipoprotein was shown to be located in close proximity to the particle surface. We suggest that this surface-exposed cysteine of apoprotein B-100 serves as a component for the disulfide linkage to apoprotein(a) in lipoprotein(a).
authors.affiliation: Institut für Biochemie, Technische Universität Graz, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Sommer
authors.forename: R
authors.initials: R
authors.lastname: Gorges
authors.forename: G M
authors.initials: GM
authors.lastname: Kostner
authors.forename: F
authors.initials: F
authors.lastname: Paltauf
authors.forename: A
authors.initials: A
authors.lastname: Hermetter
mesh_terms: D015081:2-Naphthylamine / Q000031:analogs & derivatives; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000097:blood / Q000737:chemistry*; D001665:Binding Sites; D004220:Disulfides / Q000032:analysis*; D006801:Humans; D007546:Isoquinolines; D017270:Lipoprotein(a); D008074:Lipoproteins / Q000097:blood / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence
chemical_list: D053299:Apolipoprotein B-100; D001055:Apolipoproteins B; D004220:Disulfides; D007546:Isoquinolines; D017270:Lipoprotein(a); D008074:Lipoproteins; C038518:acrylodan; C017475:lucifer yellow; D015081:2-Naphthylamine