Allowance for the effect of protein charge in the characterization of nonideal solute self-association by sedimentation equilibrium

2010 ◽  
Vol 149 (3) ◽  
pp. 83-91 ◽  
Author(s):  
David J. Scott ◽  
Peter R. Wills ◽  
Donald J. Winzor
Keyword(s):  
Sedimentation Equilibrium ◽  
Protein Charge ◽  
Self Association

scholarly journals Characterization of Native Reversible Self-Association of a Monoclonal Antibody Mediated by Fab-Fab Interaction

2020 ◽  
Vol 109 (1) ◽  
pp. 443-451 ◽  
Author(s):  
Lorenzo Gentiluomo ◽  
Dierk Roessner ◽  
Werner Streicher ◽  
Sujata Mahapatra ◽  
Pernille Harris ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Self Association

Synthesis and characterization of novel dibenz[a,c]anthracenedicarboxythioimides: the effect of thionation on self-assembly

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 78784-78790 ◽  
Author(s):  
Katie. M. Psutka ◽  
Kenneth E. Maly
Keyword(s):  
Self Assembly ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Crystalline Phases ◽  
Liquid Crystalline Phases ◽  
Self Association

The effect of thionation on the formation of columnar liquid crystalline phases of dibenzanthracenedicarboximides as well as their self-association in solution is described.

scholarly journals Purification and characterization of a heat-stable esterase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius

1988 ◽  
Vol 250 (2) ◽  
pp. 453-458 ◽  
Author(s):  
H Sobek ◽  
H Görisch
Keyword(s):  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sulfolobus Acidocaldarius ◽  
Sedimentation Equilibrium ◽  
Prolonged Storage ◽  
Heat Stable ◽  
Equilibrium Data ◽  
Poly Ethylene ◽  
Hydrolysis Of

A heat-stable esterase has been purified 1080-fold to electrophoretic homogeneity from Sulfolobus acidocaldarius, a thermoacidophilic archaebacterium; 20% of the starting activity is recovered. The purified enzyme shows a specific activity of 158 units/mg, based on the hydrolysis of p-nitrophenyl acetate. The esterase hydrolyses short-chain p-nitrophenyl esters, aliphatic esters and triacylglycerols. It is strongly inhibited by paraoxon and phenylmethanesulphonyl fluoride, but only weakly by eserine. From sedimentation-equilibrium data and molecular sieving in polyacrylamide gels, the Mr of the esterase is estimated to be 117000-128000. SDS/polyacrylamide-gel electrophoresis reveals a single band of protein, of Mr 32000. The purified esterase crystallizes in the presence of poly(ethylene glycol) in short rods. The enzyme is inactivated only on prolonged storage at temperature above 90 degrees C.

scholarly journals Studies on the antigenic determinants in the self-association of IgG rheumatoid factor

1981 ◽  
Vol 154 (1) ◽  
pp. 112-125 ◽  
Author(s):  
FA Nardella ◽  
DC Teller ◽  
M Mannik
Keyword(s):  
Sedimentation Equilibrium ◽  
Antigenic Determinants ◽  
Fab Fragment ◽  
Fab Fragments ◽  
Polymer Formation ◽  
Igg Rheumatoid Factor ◽  
Normal Human ◽  
Self Association ◽  
Equilibrium Ultracentrifugation ◽  
Antigen Antibody

The number, location, and other characteristics of the antigenic determinants for self-association of IgG-rheumatoid factors (IgG-RF) were examined using the IgG-RF isolated from the plasma of one patient as a model system. Affinity chromatography was employed for isolation of the IgG-RF. Sedimentation equilibrium ultracentrifugation was used to study the various interactions. The antigenic valence of IgG-RF Fc, normal human Fc, and rabbit Fc fragments was two for the interaction with Fab fragments from IgG-RF, as might be expected from the molecular symmetry of IgG. The antigenic valence of intact normal IgG, however, was only one, indicating that when one of the available antigenic determinants interacted with the Fab fragment of IgG-RF, the other determinant becomes sterically inaccessible. Reduction and alkylation, known to increase the flexibility of the hinge region, did not alter the antigenic valence of IgG for Fab fragments of IgG-RF. The antigenic valence of IgG-RF in self-association could not be experimentally determined but must be two to permit the observed concentration-dependent further polymer formation of IgG-RF dimers. Unique antigenic determinants on the Fc fragments of IgG-RF were sought and not found, thus reaffirming the formation of two antigen-antibody bonds as the basis for dimerization of IgG-RF molecules. The pFc' and Fc' fragments, representing Cγ3 domains of IgG, failed to show significant interaction with Fab fragments of IgG-RF, indicating that the antigenic determinants were not expressed by the Cγ3 regions but are located either on Cγ2 region or require intact Cγ2 and Cγ3 regions for expression. These conclusions were corroborated by the antigenic valence of one for the Fc(i) fragment, a new papain-generated intermediate fragment of Fc, composed of two intact Cγ3 domains and one intact Cγ2 domain. Normal IgG, because of its valence of one for interaction with IgG-RF, would effectively terminate further polymerization of IgG-RF dimers. This may well in part explain the finding of smaller IgG-RF complexes in the serum than in synovial fluid of patients with rheumatoid arthritis.

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