Advances in Desmuramyl Peptide Research

Immune adjuvants are added to vaccines in order to enhance the immune response to an antigen. Muramyl dipeptide, N-acetylmuramyl-L-alanyl-D-isoglutamine, is the smallest structural unit of peptidoglycans showing the immunostimulating activity. Muramyl dipeptide analogues without the hydrophilic N-acetylmuramyl moiety are called desmuramyl peptides. Here, we provide review of desmuramyl peptides which were synthesized in order to improve the pharmacological properties of parent muramyl dipeptide, including our results regarding adamantane containing derivatives. Approach for future design of novel immunostimulators based on multiple pathogen recognition receptor activation was also considered. This work is licensed under a Creative Commons Attribution 4.0 International License

Synthesis and Immunological Evaluation of Mannosylated Desmuramyl Dipeptides Modified by Lipophilic Triazole Substituents

Muramyl dipeptide (N-acetylmuramyl-L-alanyl-D-isoglutamine, MDP) is the smallest pep- tidoglycan fragment able to trigger an immune response by activating the NOD2 receptor. Structural modification of MDP can lead to analogues with improved immunostimulating properties. The aim of this work was to prepare mannosylated desmuramyl peptides (ManDMP) containing lipophilic triazole substituents to study their immunomodulating activities in vivo. The adjuvant activity of the prepared compounds was evaluated in the mouse model using ovalbumin as an antigen and compared to the MDP and referent adjuvant ManDMPTAd. The obtained results confirm that the α-position of D-isoGln is the best position for the attachment of lipophilic substituents, especially adamantylethyl triazole. Compound 6c exhibited the strongest adjuvant activity, comparable to the MDP and better than referent ManDMPTAd

Synthesis, structural characterization and biological activity of mannosylated desmuramyl peptides

U disertaciji je opisana sinteza novih desmuramil-peptida s ugrađenim adamantanskim aminokiselinama te manoznih derivata peptida s ciljem istraživanja njihovih imunomodulacijskih svojstava i strukturnih karakteristika. Sinteza peptida i glikopeptida je optimirana. Imunomodulacijska aktivnost desmuramil-peptida s ugrađenom 2-aminoadamantan-2-karboksilnom kiselinom i manoznih derivata ispitana je in vivo u mišjem modelu. Učinci sintetiziranih spojeva određeni su temeljem izmjerene ukupne količine specifičnih anti-OVA IgG antitijela i potklasa IgG antitijela te uspoređeni s aktivnošću literaturno opisanog ManAdDMP adjuvanta. Manozilirani derivati pokazali su pojačanu imunostimulacijsku aktivnost, dok se dimanozilirani derivat pokazao najaktivnijim adjuvantom ove serije spojeva. U disertaciji je opisana i sustavna konformacijska analiza odabranih desmuramil-peptida u vodi i DMSO primjenom računalnih metoda i spektroskopije NMR. Provedene su i molekulsko-dinamičke simulacije kompleksa manoziliranih desmuramil-peptida i intaktnog NOD2 receptora te su identificirane ključne aminokiseline za vezanje ove klase spojeva na receptor.In the thesis the synthesis of new desmuramyl peptides with incorporated adamantane amino acids and their mannose peptide derivatives is described. Compounds are prepared in order to investigate their immunomodulatory properties and structural characteristics. Peptide and glycopeptide synthesis were optimized and obtained products were structurally characterized. The immunomodulatory activity of desmuramyl peptides with incorporated 2-aminoadamantane-2-carboxylic acid and mannose derivatives was examined in vivo using a mouse model. The effects of the compounds were determined based on the total amount of specific anti-OVA IgG antibodies and subclasses of IgG antibodies and compared with the activity of the known ManAdDMP adjuvant. Mannosylated derivatives showed enhanced immunostimulatory activity, while the dimanosylated derivative proved to be the most active adjuvant. In the thesis a systematic conformational analysis of selected desmuramyl peptides in water and DMSO was performed using computational modeling and NMR spectroscopy. Molecular dynamics simulations of mannosylated desmuramyl peptide complexes with intact NOD2 receptor were also performed, and key amino acid residues involved in binding have been identified

Synthesis, structural characterization and biological activity of mannosylated desmuramyl peptides

U disertaciji je opisana sinteza novih desmuramil-peptida s ugrađenim adamantanskim aminokiselinama te manoznih derivata peptida s ciljem istraživanja njihovih imunomodulacijskih svojstava i strukturnih karakteristika. Sinteza peptida i glikopeptida je optimirana. Imunomodulacijska aktivnost desmuramil-peptida s ugrađenom 2-aminoadamantan-2-karboksilnom kiselinom i manoznih derivata ispitana je in vivo u mišjem modelu. Učinci sintetiziranih spojeva određeni su temeljem izmjerene ukupne količine specifičnih anti-OVA IgG antitijela i potklasa IgG antitijela te uspoređeni s aktivnošću literaturno opisanog ManAdDMP adjuvanta. Manozilirani derivati pokazali su pojačanu imunostimulacijsku aktivnost, dok se dimanozilirani derivat pokazao najaktivnijim adjuvantom ove serije spojeva. U disertaciji je opisana i sustavna konformacijska analiza odabranih desmuramil-peptida u vodi i DMSO primjenom računalnih metoda i spektroskopije NMR. Provedene su i molekulsko-dinamičke simulacije kompleksa manoziliranih desmuramil-peptida i intaktnog NOD2 receptora te su identificirane ključne aminokiseline za vezanje ove klase spojeva na receptor.In the thesis the synthesis of new desmuramyl peptides with incorporated adamantane amino acids and their mannose peptide derivatives is described. Compounds are prepared in order to investigate their immunomodulatory properties and structural characteristics. Peptide and glycopeptide synthesis were optimized and obtained products were structurally characterized. The immunomodulatory activity of desmuramyl peptides with incorporated 2-aminoadamantane-2-carboxylic acid and mannose derivatives was examined in vivo using a mouse model. The effects of the compounds were determined based on the total amount of specific anti-OVA IgG antibodies and subclasses of IgG antibodies and compared with the activity of the known ManAdDMP adjuvant. Mannosylated derivatives showed enhanced immunostimulatory activity, while the dimanosylated derivative proved to be the most active adjuvant. In the thesis a systematic conformational analysis of selected desmuramyl peptides in water and DMSO was performed using computational modeling and NMR spectroscopy. Molecular dynamics simulations of mannosylated desmuramyl peptide complexes with intact NOD2 receptor were also performed, and key amino acid residues involved in binding have been identified

Synthesis, structural characterization and biological activity of mannosylated desmuramyl peptides

U disertaciji je opisana sinteza novih desmuramil-peptida s ugrađenim adamantanskim aminokiselinama te manoznih derivata peptida s ciljem istraživanja njihovih imunomodulacijskih svojstava i strukturnih karakteristika. Sinteza peptida i glikopeptida je optimirana. Imunomodulacijska aktivnost desmuramil-peptida s ugrađenom 2-aminoadamantan-2-karboksilnom kiselinom i manoznih derivata ispitana je in vivo u mišjem modelu. Učinci sintetiziranih spojeva određeni su temeljem izmjerene ukupne količine specifičnih anti-OVA IgG antitijela i potklasa IgG antitijela te uspoređeni s aktivnošću literaturno opisanog ManAdDMP adjuvanta. Manozilirani derivati pokazali su pojačanu imunostimulacijsku aktivnost, dok se dimanozilirani derivat pokazao najaktivnijim adjuvantom ove serije spojeva. U disertaciji je opisana i sustavna konformacijska analiza odabranih desmuramil-peptida u vodi i DMSO primjenom računalnih metoda i spektroskopije NMR. Provedene su i molekulsko-dinamičke simulacije kompleksa manoziliranih desmuramil-peptida i intaktnog NOD2 receptora te su identificirane ključne aminokiseline za vezanje ove klase spojeva na receptor.In the thesis the synthesis of new desmuramyl peptides with incorporated adamantane amino acids and their mannose peptide derivatives is described. Compounds are prepared in order to investigate their immunomodulatory properties and structural characteristics. Peptide and glycopeptide synthesis were optimized and obtained products were structurally characterized. The immunomodulatory activity of desmuramyl peptides with incorporated 2-aminoadamantane-2-carboxylic acid and mannose derivatives was examined in vivo using a mouse model. The effects of the compounds were determined based on the total amount of specific anti-OVA IgG antibodies and subclasses of IgG antibodies and compared with the activity of the known ManAdDMP adjuvant. Mannosylated derivatives showed enhanced immunostimulatory activity, while the dimanosylated derivative proved to be the most active adjuvant. In the thesis a systematic conformational analysis of selected desmuramyl peptides in water and DMSO was performed using computational modeling and NMR spectroscopy. Molecular dynamics simulations of mannosylated desmuramyl peptide complexes with intact NOD2 receptor were also performed, and key amino acid residues involved in binding have been identified