Limits...
Intramolecular immunological signal hypothesis revived--structural background of signalling revealed by using Congo Red as a specific tool.

Jagusiak A, Konieczny L, Krol M, Marszalek P, Piekarska B, Piwowar P, Roterman I, Rybarska J, Stopa B, Zemanek G - Mini Rev Med Chem (2015)

Bottom Line: As a result, even low-affinity transiently binding antibodies can participate in immune complexes in the presence of Congo red, although immune complexes formed by these antibodies fail to trigger the complement cascade.This indicates that binding of antibodies to the antigen may not, by itself, fulfill the necessary conditions to generate the signal which triggers effector activity.These findings, together with the results of molecular dynamics simulation studies, enable us to conclude that, apart from the necessary assembling of antibodies, intramolecular structural changes generated by strains which associate high- affinity bivalent antibody fitting to antigen determinants are also required to cross the complement activation threshold.

View Article: PubMed Central - PubMed

Affiliation: .

ABSTRACT
Micellar structures formed by self-assembling Congo red molecules bind to proteins penetrating into function-related unstable packing areas. Here, we have used Congo red--a supramolecular protein ligand--to investigate how the intramolecular structural changes that take place in antibodies following antigen binding lead to complement activation. According to our findings, Congo red binding significantly enhances the formation of antigen-antibody complexes. As a result, even low-affinity transiently binding antibodies can participate in immune complexes in the presence of Congo red, although immune complexes formed by these antibodies fail to trigger the complement cascade. This indicates that binding of antibodies to the antigen may not, by itself, fulfill the necessary conditions to generate the signal which triggers effector activity. These findings, together with the results of molecular dynamics simulation studies, enable us to conclude that, apart from the necessary assembling of antibodies, intramolecular structural changes generated by strains which associate high- affinity bivalent antibody fitting to antigen determinants are also required to cross the complement activation threshold.

Show MeSH
Agarose gel electrophoresis of L-lambda chain and its complexes with Congo red. (A): L-lambda chain (I) and L-lambda chain –Congo red complexes (II and III) formed under increasing molar excess of dye molecules. (B): Reversal of the complexation process (III →II and I) obtained after the removal of Congo red from the isolated complex III by strong adsorption using Sephadex G25. 1. L-lambda chain(control sample) (I). 2. isolated complex (III). 3. complex (II) and the Congo red-deprived L-lambda chain (I) obtained by reversal.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4440395&req=5

Figure 4: Agarose gel electrophoresis of L-lambda chain and its complexes with Congo red. (A): L-lambda chain (I) and L-lambda chain –Congo red complexes (II and III) formed under increasing molar excess of dye molecules. (B): Reversal of the complexation process (III →II and I) obtained after the removal of Congo red from the isolated complex III by strong adsorption using Sephadex G25. 1. L-lambda chain(control sample) (I). 2. isolated complex (III). 3. complex (II) and the Congo red-deprived L-lambda chain (I) obtained by reversal.

Mentions: Studies concerning the localization of complexed Congo red dye in immunoglobulin domains have been performed using monoclonal L chains purified from the urine of patients suffering from multiple myeloma. Two electrophoretically differentiated complexes (representing slow- and fast-migrating fractions) were distinguished by heating L λ chain dimers in the presence of Congo red, or incubating them under increasing dye concentrations (Fig. 4). Structural analysis of protein-Congo red complexes enabled us to localize Congo red ligands in V domains.


Intramolecular immunological signal hypothesis revived--structural background of signalling revealed by using Congo Red as a specific tool.

Jagusiak A, Konieczny L, Krol M, Marszalek P, Piekarska B, Piwowar P, Roterman I, Rybarska J, Stopa B, Zemanek G - Mini Rev Med Chem (2015)

Agarose gel electrophoresis of L-lambda chain and its complexes with Congo red. (A): L-lambda chain (I) and L-lambda chain –Congo red complexes (II and III) formed under increasing molar excess of dye molecules. (B): Reversal of the complexation process (III →II and I) obtained after the removal of Congo red from the isolated complex III by strong adsorption using Sephadex G25. 1. L-lambda chain(control sample) (I). 2. isolated complex (III). 3. complex (II) and the Congo red-deprived L-lambda chain (I) obtained by reversal.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440395&req=5

Figure 4: Agarose gel electrophoresis of L-lambda chain and its complexes with Congo red. (A): L-lambda chain (I) and L-lambda chain –Congo red complexes (II and III) formed under increasing molar excess of dye molecules. (B): Reversal of the complexation process (III →II and I) obtained after the removal of Congo red from the isolated complex III by strong adsorption using Sephadex G25. 1. L-lambda chain(control sample) (I). 2. isolated complex (III). 3. complex (II) and the Congo red-deprived L-lambda chain (I) obtained by reversal.
Mentions: Studies concerning the localization of complexed Congo red dye in immunoglobulin domains have been performed using monoclonal L chains purified from the urine of patients suffering from multiple myeloma. Two electrophoretically differentiated complexes (representing slow- and fast-migrating fractions) were distinguished by heating L λ chain dimers in the presence of Congo red, or incubating them under increasing dye concentrations (Fig. 4). Structural analysis of protein-Congo red complexes enabled us to localize Congo red ligands in V domains.

Bottom Line: As a result, even low-affinity transiently binding antibodies can participate in immune complexes in the presence of Congo red, although immune complexes formed by these antibodies fail to trigger the complement cascade.This indicates that binding of antibodies to the antigen may not, by itself, fulfill the necessary conditions to generate the signal which triggers effector activity.These findings, together with the results of molecular dynamics simulation studies, enable us to conclude that, apart from the necessary assembling of antibodies, intramolecular structural changes generated by strains which associate high- affinity bivalent antibody fitting to antigen determinants are also required to cross the complement activation threshold.

View Article: PubMed Central - PubMed

Affiliation: .

ABSTRACT
Micellar structures formed by self-assembling Congo red molecules bind to proteins penetrating into function-related unstable packing areas. Here, we have used Congo red--a supramolecular protein ligand--to investigate how the intramolecular structural changes that take place in antibodies following antigen binding lead to complement activation. According to our findings, Congo red binding significantly enhances the formation of antigen-antibody complexes. As a result, even low-affinity transiently binding antibodies can participate in immune complexes in the presence of Congo red, although immune complexes formed by these antibodies fail to trigger the complement cascade. This indicates that binding of antibodies to the antigen may not, by itself, fulfill the necessary conditions to generate the signal which triggers effector activity. These findings, together with the results of molecular dynamics simulation studies, enable us to conclude that, apart from the necessary assembling of antibodies, intramolecular structural changes generated by strains which associate high- affinity bivalent antibody fitting to antigen determinants are also required to cross the complement activation threshold.

Show MeSH