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Light scattering studies of bovine skin proteodermatan sulfate
Author(s) -
Zangrando David,
Gupta Rekha,
Jamieson Alex M.,
Blackwell John,
Scott Paul G.
Publication year - 1989
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360280710
Subject(s) - chemistry , radius of gyration , guanidine , hydrodynamic radius , static light scattering , crystallography , circular dichroism , monomer , dermatan sulfate , covalent bond , light scattering , analytical chemistry (journal) , chromatography , scattering , chondroitin sulfate , copolymer , polymer , glycosaminoglycan , biochemistry , organic chemistry , optics , physics
The proteodermatan sulfate (PDS) of bovine skin is a low molecular weight proteoglycan with a molecular structure consisting of a protein chain and a sulfated polysaccharide chain covalently linked at the 4‐serine of the protein. Static and dynamic laser light scattering methods have been used to determine the weight‐average molecular weight, M w , z ‐average radius of gyration, R g z′, and z ‐average translational diffusion coefficient, D t , z °, of bovine skin PDS. We have also characterized the two components of PDS, i.e., the protein core and the dermatan sulfate (DS) chain. (The latter contained an N‐terminal‐linked penta‐ or tetrapeptide.) Interpretation of the PDS data is complicated by the block copolymer nature of its structure. When appropriate corrections are made, our results indicate that M w for PDS monomer is 62,000 when dissolved in 4 M guanidine hydrochloride (GdnHCl), and increases to 610,000 in 0.15 M NaCl. M w for the core protein in 4 M GdnHCl is 39,000, and this also increases substantially to 650,000 in 0.15 M NaCl. In contrast, M w for the DS chain is 24,000 in 0.15 M NaCl, indicating that there is minimal self‐association of DS in 0.15 M NaCl. Thus we conclude that the self‐association of PDS involves the protein core. Comparison of R g zand R h , the average hydrodynamic radius, suggests that trace amounts of aggregation persist for the PDS and its core protein even in 4 M GdnHCl. This conclusion is supported by evaluation of the second moments of the dynamic light scattering correlation function. Comparisons of the observed D t , z ° for PDS with predicted values using hydrodynamic theory are consistent with a “lollipop” conformation for the molecule.