Role of peptide bond in the realization of biological activity of short peptides

We performed a comparative analysis of biological activity of Lys-Glu peptide and its amino acid constituents. It was established that Lys-Glu stimulated proliferation of splenic cells in organotypic culture, while the mixture of glutamic acid and lysine inhibited culture growth. Using the method of molecular docking, we showed that glutamic acid, lysine, and Lys-Glu peptide can interact with different DNA sequences. The energy of interaction and the most beneficial localization of glutamic acid, lysine, and Lys-Glu peptide in DNA molecule was calculated. We demonstrated the interaction of the peptide and amino acids with DNA along the minor groove. The energy of DNA interaction with the peptide is higher than with individual amino acids. The peptide bonds increase the interaction of Lys-Glu peptide with DNA, which potentiates the biological effect on cell proliferation in organotypic culture of splenic cells.

Biological activity of amino acids in organotypic tissue cultures

We studied the effect of 20 standard L-amino acids on proliferation of the nervous, cardiovascular, urogenital, digestive, and immune system tissues from young and old animals in organotypic cultures. The effect of amino acids on tissue culture proliferation depended on their origin and animal age.

Immunomodulating effects of Vilon and its analogue in the culture of human and animal thymus cells

We studied molecular mechanisms of immunoprotective effects of two dipeptides, AB-O and R-1, on cultured human and rat thymic cells. Both dipeptides were shown to increase the expression of lymphocyte differentiation marker CD5 in thymic cells. Dipeptide AB-O induced T-cells precursor differentiation towards CD4(+)T-helpers and its effect was weaker than that of dipeptide R-1. Dipeptide R-1 stimulates differentiation of CD5(+) cells to mature T-helpers and cytotoxic CD8(+) T cells and hence can be considered as a bioactive substance possessing immunomodulator and antiallergic activity.