Expression and disulfide-bond connectivity of the second ligand-binding repeat of the human LDL receptor.
The human LDL receptor (LDLR) has a binding domain which consists of seven contiguous ligand-binding (LB) repeats, each approximately 40 amino acids long with three disulfide bonds. The second LB repeat, which is required for full binding of LDL, has been expressed, purified and folded to yield a single, fully oxidized isomer. By selective reduction and alkylation, we have shown that the cysteine residues have a I-III, II-V, IV-VI connectivity, matching that recently determined for the amino-terminal repeat. We suggest that the first two LB repeats of the LDLR, with their unique disulfide-bonding pattern, serve as a structural paradigm for other LB repeats.
Bieri
S
S
Department of Biochemistry, University of Queensland, Brisbane, Australia.
Djordjevic
J T
JT
Jamshidi
N
N
Smith
R
R
Kroon
P A
PA
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003545:Cysteine / Q000378:metabolism; D017931:DNA Primers; D004220:Disulfides / Q000378:metabolism*; D004926:Escherichia coli; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D017510:Protein Folding; D011973:Receptors, LDL / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D013329:Structure-Activity Relationship
D017931:DNA Primers; D004220:Disulfides; D008024:Ligands; D011973:Receptors, LDL; D011993:Recombinant Fusion Proteins; D003545:Cysteine