scholarly journals Interactions of an intact proteoglycan and its fragments with basic homopolypeptides in dilute aqueous solution

1974 ◽  
Vol 141 (2) ◽  
pp. 445-454 ◽  
Author(s):  
Robert A. Gelman ◽  
John Blackwell ◽  
Martin B. Mathews
Keyword(s):  
Aqueous Solution ◽  
Conformational Change ◽  
Degradation Product ◽  
Nasal Septum ◽  
Chondroitin Sulphate ◽  
Side Chains ◽  
Protein Backbone ◽  
Protein Core ◽  
Helical Content ◽  
Dilute Aqueous Solution

The interactions between a proteoglycan and cationic polypeptides have been investigated by the use of circular-dichroism spectroscopy. The interaction produces an induced conformational change for poly(l-arginine) and poly(l-lysine), similar to the effects previously reported for mucopolysaccharide–polypeptide mixtures. For bovine nasal septum proteoglycan, the interactions are similar to those for chondroitin 4-sulphate, which comprises approximately 63% of the total polysaccharide. The results also suggest that the interactions produce a conformational change in the protein core. Similar studies for the Smith-degradation product show that the protein core can adopt a substantial α-helical content and is capable of interactions with poly-(l-arginine). The interactions for chondroitin sulphate ‘doublets’ are significantly different from those for the separated chains, indicating that the arrangement of the polysaccharide side chains in pairs (and larger groups) along the protein backbone contributes to the interaction properties of the intact proteoglycan.

scholarly journals Stanley Miles Partridge, 2 August 1913 - 26 April 1992

1994 ◽  
Vol 40 ◽  
pp. 327-346
Keyword(s):  
Connective Tissue ◽  
Chondroitin Sulphate ◽  
Basic Structure ◽  
Side Chains ◽  
Unusual Structure ◽  
Protein Core ◽  
The Past ◽  
Initial Representation ◽  
Bottle Brush

The explosion of interest in the connective-tissue field over the past decade is based on the early intellectual contributions of just a few pioneering investigators. Miles Partridge was one of those few. He will be best remembered for the characterization of elastin from a histological entity to a protein in its own right, and for demonstrating how its unusual structure results in a rubber-like elasticity. He also identified the glycoprotein in aortic elastin that was later shown to exist as microfibrils and to be involved in directing the elastin fibre during development. He made a major contribution to the elucidation of the basic structure of the glycosaminoglycans by his initial representation of chondroitin sulphate as a bottle-brush structure consisting of a protein core and numerous side chains of polysaccharides. He chose these topics firstly because very little was known about these structures and they were considered by his contemporaries to be insoluble problems, and secondly because it was not in his nature just to extend or confirm other people’s work. Miles Partridge clearly possessed a vision of connective tissue well ahead of his time, and his legacy has been to provide openings into areas previously thought to be intractable. He can therefore rightly be considered one of the fathers of connective-tissue biochemistry.

scholarly journals Freeze concentration of dilute aqueous solution

1968 ◽  
Vol 17 (3) ◽  
pp. 354-355 ◽  
Author(s):  
Atsushi MIZUIKE ◽  
Shigeki KANO
Keyword(s):  
Aqueous Solution ◽  
Freeze Concentration ◽  
Dilute Aqueous Solution

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

Determination of the complexation properties of a crosslinked poly(acrylic acid) gel with copper(II), nickel(II), and lead(II) in dilute aqueous solution

2001 ◽  
Vol 79 (4) ◽  
pp. 370-376 ◽  
Author(s):  
Catherine Morlay ◽  
Yolande Mouginot ◽  
Monique Cromer ◽  
Olivier Vittori
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Acrylic Acid ◽  
Metal Ion ◽  
Conditional Stability ◽  
Binding Properties ◽  
Complex Species ◽  
Complexing Capacity ◽  
Dilute Aqueous Solution ◽  
Poly Acrylic Acid

The possible removal of copper(II), nickel(II), or lead(II) by an insoluble crosslinked poly(acrylic acid) was investigated in dilute aqueous solution. The binding properties of the polymer were examined at pH = 6.0 or 4.0 with an ionic strength of the medium µ = 0.1 or 1.0 M (NaNO3) using differential pulse polarography as an investigation means. The highest complexing capacity of the polyacid was obtained with lead(II) at pH = 6.0 with µ = 0.1 M, 4.8 mmol Pb(II)/g polymer. The conditional stability constants of the complex species formed were determined using the method proposed by Ruzic assuming that only the 1:1 complex species was formed; for lead(II) at pH = 6.0 and µ = 0.1 M, log K' = 5.3 ± 0.2. It appeared that the binding properties of the polymer increased, depending on the metal ion, in the following order: Ni(II) < Cu(II) < Pb(II). The complexing capacity and log K' values decreased with the pH or with an increase of the ionic strength. These results were in agreement with the conclusions of our previous studies of the hydrosoluble linear analogues. Finally, with the insoluble polymer, the log K' values were comparable to those previously obtained with the linear analogue whereas the complexing capacity values expressed in mmol g-1 were slightly lower.Key words: insoluble crosslinked poly(acrylic acid), copper(II), nickel(II), and lead(II) complexation.

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