NMR studies of peptides derived from the putative binding regions of cartilage proteins. No evidence for binding to hyaluronan.
Previous work has implicated sequences within the tandem repeats of cartilage link protein in the interaction of link protein with hyaluronan. This conclusion was based on competitive inhibition experiments using synthetic peptides (Goetinck, P. F., Stirpe, N. S., Tsonis, P. A., and Carlone, D. (1987) J. Cell Biol. 105, 2403-2407). Further investigation of this system using high resolution nuclear magnetic resonance, circular dichroism, and competitive inhibition with other peptides indicates that the previously observed inhibition of link protein-hyaluronan binding was not caused by peptide-hyaluronan interactions. Instead, nonspecific aggregation of the peptides with link protein is proposed to account for all of the experimental data. Consequently, there is no direct experimental evidence to support the conclusion that these sequences in the tandem repeats of link protein are responsible for the link protein-hyaluronan interaction. If these peptides do represent the hyaluronan binding regions of link protein, these results imply a highly structure-dependent interaction between link protein and hyaluronan. Conformational analysis of the peptides using two-dimensional nuclear Overhauser spectroscopy indicates that the linear peptides do not adopt any stable secondary structure. However, several residues in the disulfide-looped peptides exhibit connectivities, suggesting a relatively long-lived extended chain conformation, consistent with predictions of secondary structure based on sequence analysis.
Horita
D A
DA
Department of Chemistry, University of Wisconsin, Madison 53706.
Hajduk
P J
PJ
Goetinck
P F
PF
Lerner
L E
LE
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002356:Cartilage / Q000378:metabolism*; D016326:Extracellular Matrix Proteins; D006820:Hyaluronic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008961:Models, Structural; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D011509:Proteoglycans / Q000737:chemistry*; D000099249:Proteoglycan Link Protein
D016326:Extracellular Matrix Proteins; D006820:Hyaluronic Acid; D010446:Peptide Fragments; D010455:Peptides; D011506:Proteins; D011509:Proteoglycans; D000099249:Proteoglycan Link Protein