Interaction of antibodies and antigens conjugated with synthetic polyanions: on the way of creating an artificial chaperone

• Published in: Biochimica et biophysica acta Vol. 1475; no. 2; pp. 141 - 150
• Main Authors: Muronetz, Vladimir I., Kazakov, Sergey V., Dainiak, Maria B., Izumrudov, Vladimir A., Galaev, Igor Yu, Mattiasson, Bo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 03.07.2000
• Subjects: Anions; Antibodies - chemistry; Antigen-Antibody Reactions; Artificial chaperone; Chemical Precipitation; Glyceraldehyde-3-phosphate dehydrogenase; Glyceraldehyde-3-Phosphate Dehydrogenases - chemistry; Hydrogen-Ion Concentration; Light scattering; Models, Molecular; Molecular Chaperones - chemical synthesis; Monoclonal antibody; Particle Size; Polymethacrylic Acids - chemistry; Protein Conformation; Spectrophotometry, Ultraviolet; Synthetic polyanion; PEC, polyelectrolyte complex; GAPDH, glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12); Light scattering; PEVP, poly( N-ethyl-4-vinylpyridinium bromide); Monoclonal antibody; Synthetic polyanion; PMAA, poly(methacrylic acid); DTT, dithiothreitol; mPEVP, modified poly( N-ethyl-4-vinylpyridinium bromide) with 7% hydroxyethyl groups; LS, light scattering; dGAPDH, denatured form of GAPDH; Artificial chaperone; Glyceraldehyde-3-phosphate dehydrogenase
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/S0304-4165(00)00060-X

Recently we have initiated the use of synthetic polyelectrolytes to mimic the action of chaperones in living cells [Dainiak et al., Biochim. Biophys. Acta 1381 (1998) 279–285]. The next step in this direction is done by the synthesis of conjugates of poly(methacrylic acid) (PMAA) with antigen, denatured glyceraldehyde-3-phosphate dehydrogenase (dGAPDH), and with monoclonal antibodies specific for dGAPDH (but not for the native protein). The pH-dependent properties of the conjugates have been studied using turbidimetry and light scattering. The antibody–PMAA and dGAPDH–PMAA conjugates were shown to interact with free dGAPDH and antibodies respectively as well as with each other. Insoluble aggregates of dGAPDH with antibody–PMAA and of antibodies with dGAPDH–PMAA are formed in acidic media. The same situation occurs in the mixture of antibody–PMAA and dGAPDH–PMAA: precipitation takes place in acidic media, whereas soluble associates are formed in neutral solutions. The size of the soluble associates and the number of conjugates in the associate could be regulated by pH. The competition of free dGAPDH and dGAPDH–PMAA for binding with antibody–PMAA and the dynamic release of refolded GAPDH, with no affinity to antibody–PMAA, into solution could be used for simulating chaperone action.