[A protein interaction network and cell signaling pathways activated by muramyl peptides].

Review is devoted to studying the interaction muramyl peptides with protein components of immune system cells. Systems analysis of published results may be useful to select not only the strategy to further explore the function of this class of glycopeptides, but their use in clinical practice.

[Structure-functional study of glycosaminylmuramoyl peptides. The effect of chemical modification of N-acetylglucosaminyl-N-acetylmuramoyldipeptide on its immunomodulating properties in vivo and in vitro]. / Strukturno-funktsional'noe issledovanie gliukozaminilmuramoilpeptidov. Vliianie khimicheskoi modifikatsii N-atsetilgliukozaminil-N-atsetilmuramoildipeptida na ego immunomoduliruiushchie svoistva in vivo i in vitro.

The structure-function relationships in a series of synthetic glucosaminylmuramyl peptides--glycopeptide adjuvants of the bacterial origin--have been investigated. Modification of the N-acetylglucosaminyl-(beta 1-4)-N-acetylmuramyl-L-alanyl-D-isoglutamine (GMDP) molecule affects its adjuvant and pyrogenic activity in vivo. GMDP is shown to readily stimulate the synthesis of the IgG2a and IgG3 of the immunoglobulin subclasses upon the secondary immune response to the protein antigen. The adjuvant effect correlates with the comitogenic test of the reaction of splenocytes blast-transformation in the presence of B-cell mitogen. No direct dependence has been revealed between the level of the glycopeptides adjuvant action and their effect on the IL-1 production by macrophages.

[Use of synthetic carriers and adjuvants for increasing the immunogenicity of a synthetic peptide from the CS-protein of Plasmodium falciparum]. / Ispol'zovanie sinteticheskikh nositelei i ad''iuvantov dlia povysheniia immunogennosti sinteticheskogo peptida iz CS-belka Plasmodium falciparum.

In order to increase immunogenicity of the peptide (NANP)3, we have prepared a large set of fully synthetic constructions based on the peptide, glycopeptide adjuvant GMDP and some synthetic carriers. Immunogenicity of these constructions was tested on mice (line C57B1/6) responding to the peptide polymer (NANP)40 without carrier and on mice (line BALB/c) not responding to this antigen. Immunogenic constructions based on synthetic polytuftsin induced as high titres of anti-(NANP)3 antibodies as the standard conjugate KLH--(NANP)3. The chimeric peptide consisting of (NANP)3 and tuftsin dimer induced anti-(NANP)3 antibodies in both lines of mice as well. The GMDP covalent attachment to the immunogenic constructions increased the antipeptide antibodies titre. The results are discussed in terms of an approach to synthetic vaccines.

[Synthetic immunogenic complexes containing a peptide from the surface protein of the foot-and-mouth disease virus]. / Sinteticheskie immunogennye kompleksy na osnove peptida poverkhnostnogo belka virusa iashchera.

Synthetic constructions containing a peptide antigenic determinant (C-terminal peptide 205-213 of the surface VP1 protein of the foot-and-mouth disease virus, O1K strain), glucosaminylmuramayl dipeptide (GMDP), and polyionic synthetic carriers were prepared. The polymerized peptide and peptide-BSA conjugates were synthesized as well. Among the constructions obtained only peptide-BSA conjugate proved to be highly immunogenic. Application of synthetic constructions to design immunogenic complexes is discussed.

[Dependence of pepsin conformational states on pH and temperature]. / Konformatsionnye sostoianiia pepsina v zavisimosti ot pH i temperatury.

A conformational behaviour of pepsin depending on pH and temperature was studied by circular dichroism, differential UV-spectroscopy, calorimetry and enzymatic hydrolysis kinetics. A subtile conformational transition of the enzyme accompanied by changes in the physico-chemical and enzymatic properties of the protein was observed within the temperature interval of 15--40 degrees and within the pH range of 1,1--5,6. The range of pepsin heat denaturation was studied. A diagram of pepsin conformational states under different values of pH and temperature was built.