The Immunoglobulin Heavy Chain Constant Region Affects Kinetic and Thermodynamic Parameters of Antibody Variable Region Interactions with Antigen
Journal of Biological Chemistry
Downloaded from FIGURE 4. Thermodynamics of binding of mAbs 3E5 to a peptide mimetic of GXM. Behavior of free energy of binding (⌬G) (A), encounter free energy of binding (⌬G 1 ) (B), docking free energy of binding (⌬G 2 ) (C), and entropy of binding (⌬S) (D) as a function of temperature for the mAb 3E5 binding to peptide P1. Free energies were calculated from the formula ⌬G ϭ ϪRTlnK A , ⌬G ϭ ϪRTlnK a1 , ⌬G ϭ ϪRTlnK a2 , and ⌬S is from the formula ⌬G ϭ ⌬H Ϫ T⌬S. Downloaded from FIGURE 6.
... om FIGURE 6. Homology modeling analysis of mAb 3E5 C H1 domain. Magnified views of regions A, B, and C are showed in panels A, B, and C, respectively. Side chains of amino acids with structural differences between C H1 domains of different IgG isotypes are indicated by arrows. D, amino acid connectivity analysis of mAb 3E5 IgG 1 . Areas of high connectivity are indicted by red and orange (red, Zscore Ͼ 2.0; orange, 1.5 Ͻ Zscore Ͻ 2.0). Medium connectivity residues are indicated in yellow (1.0 Ͻ Zscores Ͻ 1.5), and low connectivity is indicated in blue (Zscore Ͻ 1.0). Light chain is shown in gray. Amino acids Asp 180 and Thr 183 are located in the orange area and are indicated by arrows. This figure was generated using PyMOL. Downloaded from FIGURE 8. Reactivity patterns of mAbs 3E5 against polyreactive antigens. Panels corresponds to the binding profiles of 3E5 IgG switch variants to: A, thyroglobulin; B, double-stranded DNA; C, tubulin; D, actin; E, single-stranded DNA. Anti-GXM mAb 18B7 (IgG 1 ) was added as control. Data represent the mean Ϯ S.D. of three measurements.