Structural changes of IgG induced by heat treatment and by adsorption onto a hydrophobic Teflon surface studied by circular dichroism spectroscopy.

Thermal denaturation of mouse monoclonal immunoglobulin G (isotype 1), as well as structural rearrangements resulting from adsorption on a hydrophobic Teflon surface, are studied by circular dichroism spectroscopy. Both heat-induced and adsorption-induced denaturation do not lead to complete unfolding into an extended polypeptide chain, but leave a significant part of the IgG molecule in a globular or corpuscular form. Heating dissolved IgG causes a decrease of the fractions of beta-sheet and beta-turn conformations, whereas those of random coil and, to a lesser extent, alpha-helix increase. Adsorption enhances the formation of alpha-helices and random coils, but the beta-sheet content is strongly reduced. Heating adsorbed IgG results in a gradual break-down of the alpha-helix and beta-turn contents, and a concomitant formation of beta-sheet structures. Thus, the structural changes in IgG caused by heating and by adsorption, respectively, are very different. However, after heating, the structure of adsorbed IgG approaches the structure of thermally denatured IgG in solution.

[1]  C. Chothia,et al.  Domain association in immunoglobulin molecules. The packing of variable domains. , 1985, Journal of molecular biology.

[2]  J Deisenhofer,et al.  Crystallographic refinement and atomic models of the intact immunoglobulin molecule Kol and its antigen-binding fragment at 3.0 A and 1.0 A resolution. , 1980, Journal of molecular biology.

[3]  B. Singh,et al.  FT-IR in Combination with the Attenuated Total Reflectance Technique: A Very Sensitive Method for the Structural Analysis of Polypeptides , 1991 .

[4]  J. M. Peula,et al.  Coadsorption of IgG and BSA onto sulfonated polystyrene latex: I. Sequential and competitive coadsorption isotherms. , 1995, Journal of biomaterials science. Polymer edition.

[5]  P. Privalov,et al.  A thermodynamic study of cooperative structures in rabbit immunoglobulin G. , 1982, European journal of biochemistry.

[6]  W. Heuvelsland,et al.  Adsorption and immunoreactivity of proteins on polystyrene and on silica. Competition with surfactants , 1993 .

[7]  W. Norde,et al.  Changes in the secondary structure of adsorbed IgG and F(ab')2 studied by FTIR spectroscopy. , 1996 .

[8]  G. Fasman Circular Dichroism and the Conformational Analysis of Biomolecules , 1996, Springer US.

[9]  P. Privalov Scanning microcalorimeters for studying macromolecules , 1980 .

[10]  G. Fasman,et al.  Computed circular dichroism spectra for the evaluation of protein conformation. , 1969, Biochemistry.

[11]  G. J. Fleer,et al.  Reflectometry as a tool for adsorption studies , 1994 .

[12]  C. Haynes,et al.  Globular proteins at solid/liquid interfaces , 1994 .

[13]  S. Martsev,et al.  Thermodynamic and functional characterization of a stable IgG conformer obtained by renaturation from a partially structured low pH‐induced state , 1995, FEBS letters.

[14]  S. Raghavan,et al.  Quantitative Analysis of Adsorbed Serum Albumin on Segmented Polyurethane Using FT-IR/ATR Spectroscopy , 1992 .

[15]  J. T. Yang,et al.  Circular dichroic analysis of protein conformation: inclusion of the beta-turns. , 1978, Analytical biochemistry.

[16]  J. Killian,et al.  Analysis of circular dichroism spectra of oriented protein-lipid complexes: toward a general application. , 1994, Biochemistry.

[17]  M. L. Connolly Analytical molecular surface calculation , 1983 .

[18]  W. Norde The Behavior of Proteins at Interfaces, with Special Attention to the Role of the Structure Stability of the Protein Molecule , 1992 .

[19]  Lin Ds,et al.  Circular dichroism spectroscopy of monoclonal antibodies that bind a superpotent guanidinium sweetener ligand. , 1996 .

[20]  J. Koenig,et al.  The Variable-Temperature FT-IR Study of the Secondary Structure of γ-Globulin, Chymotrypsin, Serum Albumin, and β-Lactoglobulin in Aqueous Solution , 1989 .

[21]  G. Barone,et al.  DSC studies on the denaturation and aggregation of serum albumins , 1992 .

[22]  B. Wesslén,et al.  Adsorption behaviour of amphiphilic polymers at hydrophobic surfaces: effects on protein adsorption. , 1996, Biomaterials.

[23]  R. Jaenicke,et al.  Alternatively folded states of an immunoglobulin. , 1991, Biochemistry.

[24]  T. Gribnau,et al.  Characterization of monoclonal antibodies physically adsorbed onto polystyrene latex particles. , 1992, Journal of immunological methods.

[25]  W. Norde,et al.  Driving forces for protein adsorption at solid surfaces , 1996 .

[26]  J. Brahms,et al.  Determination of protein secondary structure in solution by vacuum ultraviolet circular dichroism. , 1980, Journal of molecular biology.

[27]  W. Norde,et al.  Adsorption Dynamics of IgG and Its F(ab′)2and Fc Fragments Studied by Reflectometry , 1996 .

[28]  J. Rousseaux,et al.  Comparative study of the conformational features of rat immunoglobulin G subclasses by circular dichroism. , 1982, Biochimica et biophysica acta.

[29]  A. Visser,et al.  Spectroscopic investigation of the structure of a protein adsorbed on a hydrophobic latex , 1996 .

[30]  W. Norde,et al.  Adsorption of monoclonal IgGs and their F(ab′)2 fragments onto polymeric surfaces , 1995 .

[31]  B. Wesslén,et al.  Protein adsorption of poly(ether urethane) surfaces modified by amphiphilic and hydrophilic polymers. , 1994, Biomaterials.

[32]  Sang Hwan Lee,et al.  Adsorption of proteins onto polymeric surfaces of different hydrophilicities—a case study with bovine serum albumin , 1988 .

[33]  W. Norde,et al.  Adsorption competition between albumin and monoclonal immuno-gamma-globulins on polystyrene latices , 1992 .

[34]  P. A. Martic,et al.  Protein adsorption on pluronic copolymer-coated polystyrene particles , 1989 .

[35]  A. Drake,et al.  Spectroscopic studies on IgG aggregate formation. , 1989, Molecular immunology.

[36]  A. Wada,et al.  Secondary structural changes of large and small fragments of bovine serum albumin in thermal denaturation and in sodium dodecyl sulfate denaturation , 1993, Journal of protein chemistry.

[37]  F. Batzer,et al.  Hormonal evaluation of early pregnancy. , 1980, Fertility and sterility.

[38]  E. Padlan,et al.  Anatomy of the antibody molecule. , 1994, Molecular immunology.

[39]  W. Norde,et al.  The effect of adsorption on the antigen binding by IgG and its F(ab')2 fragments. , 1997 .

[40]  G. Findenegg,et al.  Structure, Stability, and Activity of Adsorbed Enzymes , 1997, Journal of colloid and interface science.

[41]  P. Walstra,et al.  Estimations of the aggregation time of various colloidal systems , 1995 .

[42]  Charles A. Haynes,et al.  Structures and Stabilities of Adsorbed Proteins , 1995 .

[43]  J. Deisenhofer Crystallographic refinement and atomic models of a human Fc fragment and its complex with fragment B of protein A from Staphylococcus aureus at 2.9- and 2.8-A resolution. , 1981, Biochemistry.

[44]  H. Susi,et al.  Examination of the secondary structure of proteins by deconvolved FTIR spectra , 1986, Biopolymers.