Spectral manifestations of amino acids from immunoglobulin and tumor necrosis factor composition intermolecular interaction and effect of cyanine 7 on this interaction

Immunoglobulin and tumor necrosis factor complex formation, which is the basis of immunosuppressive drug etanercept therapeutic action, has been studied using quantum chemical modeling and molecular dynamics. The effect on the possibility of cyanine 7 on hydrogen bonds formation between amino acids from tumor necrosis factor and immunoglobulin has been considered. Analysis of dye effect on tumor necrosis factor and immunoglobulin complexation is caused by need for its use as a fluorescent label of etanercept when studying this drug passing through vessels and tissues of body in vivo. Computer simulation was based on molecular structures and IR spectra calculation using the density functional theory methods, followed by an analysis of formed hydrogen bonds parameters, as well as on the study of tumor necrosis factor protein structure dynamics. It has been found that cyanine 7 has a weak effect on amino acids complexation and, therefore, does not lead to therapeutic effect decrease, which makes it possible to use cyanine 7 for labeling etanercept.