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Potential Active Amino Acids and Peptides

#A-1677


The Synthesis of Potential Biologically Active Heterocycle Substituted a-Amino Acids and Peptides. Investigation of their Antibacterial, Antiviral and Antitumor Properties

Tech Area / Field

  • MED-RAD/Radiomedicine/Medicine
  • BIO-CHM/Biochemistry/Biotechnology
  • MED-DRG/Drug Discovery/Medicine

Status
8 Project completed

Registration date
18.09.2008

Completion date
12.11.2012

Senior Project Manager
Melnikov V G

Leading Institute
Scientific and Production Center "Armbiotechnology" NAS RA, Armenia, Yerevan

Supporting institutes

  • Research Center of Radiation Medicine and Burns, Armenia, Yerevan

Collaborators

  • Universite de Nantes / Laboratoire de Biotechnologie, France, Nantes\nUniversite de Paris-Sud / Institut de Chimie Moleculaire et des Materiaux D’Orsay, France, Orsay\nUniversité de la Méditerranée / Laboratoire AFMB, France, VIZIER\nIstituto di Chimica Biomolecolare/Consiglio Nazionale delle Ricerche (ICB-CNR), Italy, Napoli\nFacultes Universitaires Notre-Dame de la Paix Namur, Belgium, Namur

Project summary

The goal of the project is to synthesize heterocycle substituted (R) and (S)-α–amino acids and di-, tri-, tetrapeptides, containing triazole, lactone and oxazole substitutes in side-chain radicals and to investigate their antibacterial, antiviral and anti-tumor properties aimed at revealing potential compounds with pharmacological activity.

Nonprotein amino acids and peptides based thereon occupy a special place in a pattern of optically and biologically active compounds. As irreversible inhibitors of enzymes these compounds are successfully used in medicine, pharmacology and clinical diagnostics and in other fields of science. The most α-amino acids, their derivatives or peptides composed of α-amino acids are active aglycons of numerous contemporary antibacterial, antiviral and antitumor drugs [1-10]. Modern strategy of drug discovery is based on the synthesis of novel ligands and investigation of their interaction with corresponding targets. Thereupon the synthesis of new heterocyclic substituted nonprotein amino acids and peptides as the most prospective components of antibacterial, antiviral and anti-tumor drugs is an urgent problem.

The unrelenting emergence of bacterial pathogens with multiple resistance towards known antibiotics forces urgent investigation of antibiotics with a new modes of action. A number of nonprotein amino acids and peptides such as histidine-rich glycoprotein (HRGP), inhibitors of the bacterial acetyl-CoA carboxylase, CA(1-7)MEL peptide and its derivatives proved to have antibacterial activity that makes them promising class of compounds for new antibiotics design [15-18]. It is well known that some pathological conditions, in particular, viral infections are protease-aided processes. Protease inhibitors appeared as a class of medications used to treat or prevent viral infections, including HIV and Hepatitis C. Protease inhibitors prevent viral replication by inhibiting the activity of protease, an enzyme used by the viruses to cleave nascent proteins for final assembly of new virons. Peptides composed of nonprotein amino acids belonging to protease inhibitors are widely used in medicine [21-25]. Inhibitors of protein kinases, particularly inhibitors of p38 MAP kinase were shown recently to be prospective anti-inflammatory and antitumor preparations [26]. The synthesis of new heterocyclic substituted nonprotein amino acids and peptides proposed in the present project as well as the study of biological activity of new compounds, will contribute to design of novel antibacterial, antiviral and antitumor medications.

It’s worthy to note that nonprotein α-amino acids and peptides are physiologically active and eligible for application in medicine and other spheres of science only as optically pure isomers since their optical antipode, as a rule, exerts negative impact. However, because of the non-natural structure of substrates, production of nonprotein amino acids by the traditional microbiological and enzymatic synthesis is ineffective but very successful via the asymmetric synthesis.

Earlier, within the framework of International INTAS, Inco-Copernicus and ISTC (#A-356) grants the universal technology for the asymmetric synthesis of optically active (R) and (S)-α-amino acids by the chiral auxiliary (S)-2-N-(N1-benzylprolyl)aminobenzophenone (BPB) has been developed [28-34].

Within the framework of the ISTC #A-1247 project, the synthesis and screening of the nonprotein amino acids and peptides based thereon is being conducted on microbiological, biochemical and cytological models. Study of the antibacterial effect of the synthesized compounds has revealed a wide spectrum of these compounds impact. A number of nonprotein amino acids and peptides containing nonprotein amino acids were observed to inhibit the growth of Gram+ and Gram- bacteria and yeasts. In some cases the growth inhibition depends on species of tested microorganisms or on optical configuration of tested compound. [39]. For example, (R)- and (S)-stereoisomers of allylglycine were active only towards the tested Gram- bacteria. Stereospecificity of non-protein amino acids has also been revealed: out of two stereoisomers of beta-hydroxyleucine only (2S,3R)-beta-hydroxyleucine suppressed the growth of the tested cultures. The screening carried out on the biochemical model was devoted to interaction of the synthesized non-protein amino acids and peptides with serine proteases of trypsin and proteinase K. The interaction of compounds with proteases was analyzed by AutoGrid 4.0 and AutoDock 4.0 software. Biochemical investigation has shown that a number of nonprotein amino acids and peptides were inhibitors of trypsin and proteinase K. Thus, (2R,3S)-hydroxyleucine inhibited trypsin with IC50=3.2mM, and showed the enhanced inhibitory effect (IC50=0.29) in N-formyl(S)-methionyl-(2R, 3S)-hydroxyleucine dipeptide.

Study of the effect of nonprotein amino acids and peptides on proliferation of lymphocytes in mammals in vitro and in vivo (the culture of lymphocytes of human periphery blood, lab. animals’ bone marrow cells) showed that some of those compounds especially heterocyclic nonprotein amino acids in rather low concentrations (in the range of 10-6 – 10-5 g/ml) demonstarted pronounced cytogenetic activity. ??Imidazolylalanine at a certain concentration exhibited expressed stimulating effect on the growth of lymphocytes [40]. While thio-triazolylalanines reduced proliferation activity of lymphocytes, at the same time the increasing of the chromosome aberrations frequency was observed, i.e. there was a correlation between antimitogenic and mutagenic actions of these compounds. Hence, the obtained results showed that the tested heterocyclic compounds are able to regulate the cell growth and could be recommended as components of both antitumor drugs and immunomodulators. It was also demonstrated that some tested nonprotein amino acids were able to change proliferation activity of lymphocytes in human blood when radiated. These compounds might be applied in correction of radial loads on the organism during the treatment of patients with malignant tumors. It should be noted that out of all tested compounds only heterocyclic -imidazolylalanine affected NG-induced mutagenesis in microorganisms decreasing frequency of NG-induced reversions by an order.

Analysis of the data obtained within the ISTC project #A-1247 has shown that as the most perspective potential components of medications could appear heterocyclic nonprotein amino acids and peptides.

The proposed project will result in the synthesis of novel optically active heterocyclic nonprotein α-amino acids containing various substituted triazole, lactone, oxazole and other substitutes in the side chain radical (A,B,C,D), as well as di-, tri- and tetrapeptides with heterocycle substituted nonprotein amino acids. It is scheduled to synthesize N-formyl-(S)-methyonyl-(S)-A, or -B, or –С; BOC-(S)-alanyl-(S)-A, or -B, or –С; N-formyl-(S)-methyonylglycyl-(S)-A, or -B, or –С; BOC-(S)-alanylglycyl-(S)-A, or -B, or –С; N-formyl-(S)-methyonylglycyl-(S)-alanyl-(S)-A, or -B, or -С and other peptides containing nonprotein aliphatic and heterocyclic amino acids.

Study of the biological activity of the synthesized compounds will presumably reveal the growth inhibitors of microorganisms, inhibitors of serine proteases and protein kinases as well as compounds regulating the growth of lymphocytes in human periphery blood and bone marrow cells in lab. animals.

Most probably the mechanisms of the growth inhibition of microorganisms, the mechanisms of the synthesized compounds action upon serine proteases and protein kinase as well as the “dose-effect” and “structure-function” regularities under the action of the synthesized compounds upon somatic cells will be presumably revealed. The most active compounds will be recommended as medication components.

The majority of executors within the project are "weapon" scientists enabled to redirect their research activity to peaceful activities and to integrate into the International scientific community.

Taking into consideration previously obtained results as well as published data on potential targets of antitumor, anti-inflammatory and antibacterial medications, the following scope of activity is proposed:

  • to synthesize optically active heterocyclic non-protein α-amino acids containing various substituted triazole, lactone, oxazole and other substitutes in the side chain radical;
  • to synthesize di-, tri and tetrapeptides containing hetericycle substituted amino acids;
  • to study the action of the synthesized compounds on bacterial growth;
  • to study the influence of synthesized compounds on serine proteases aimed at revealing potential antiviral agents;
  • to study the influence of synthesized compounds on protein kinase p38 aimed at revealing potential anti-inflammatory agents;
  • to study compounds regulating the growth of lymphocytes in human periphery blood and bone marrow cells in lab. animals;
  • to study the effect of the synthesized compounds on lymphocytes culture in oncological patients aimed at evaluation of their cytogenetic activity in vitro; paraclinicаl testing;
  • to carry out the toxicological testing of synthesized compounds.

The antibacterial action of the synthesized compounds will be evaluated on the microbiological model (ISTC Project #А-1247). Activity of serine proteases and protein kinase p38 is supposed to determine by kits according to the methods recommended by the manufacturers. Cytogenetic characteristics will be evaluated while screening the compounds in vivo and in vitro, as well as in paraclinicаl testing in oncological patients.


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