Gerardo, Bar Ilan University
The Middle Asian tortoise (Testudo horsfieldii) is one of the highest radio resistant animals (LD 50/30 – 500Gy). We have prepared extracts from different organs of the tortoise and evaluated their biological activity. The extract derived from tortoise spleen significantly increases survival of mice treated with lethal doses of γ-irradiation[1-5].
In an iterative process, the crude extract was submitted to a number of purification steps side by side with biological activity evaluation of the so obtained fractions. The process finished up with the isolation, characterization and synthesis of a tetrapeptide. The synthetic analogue acts at concentrations as low as 1g/ml suggesting that there should be a specific mechanism of action exerted by this peptide. The peptide activates both in vivo and ex-vivo the early hematopoietic progenitor cells, thereby accelerating repopulation of the irradiated bone marrow.
The studies in experimental animals suggest that treatment with this peptides can potentially benefit patients who suffer bone marrow (BM) damage due to radiotherapy or chemotherapy as well as patients undergoing autologous or allogenic BM transplantation.
1. Turdiev, A. A., Usmanov, R. B., Madzhidova, D. Kh. and Nigmatov, Z. (1985) Radiobiology, 25, 655-659.
2. Turdiev, A. A., Prus, E. K., Brain, A. P. R. and Quinn, P.J. (1990) Tissue Cell, 22, 385-387.
3. Turdiev A.A., Usmanov R., Alexandrov V.V., Philutovich O.S. (1998) Radiation Biology and Radioecology, vol.38, 2, 63-70.
4. Turdiev A.A. et al. (2000) Blood, vol.96, 11, nov.16, p.156-157
5. Turdiev A.A., Agent Derived from Tortoise Spleen Stimulating Mammalian Hemopoiesis. Patent # 157772, 04-09-2003, Israel.
Prof. Gerardo Byk received his B.Sc., M.Sc. and Ph.D. (suma cum laude) at the Hebrew University of Jerusalem. In his PhD work he developed a new generation of peptidomimetic molecules by the introduction of the new concept of backbone cyclization. This approach was extensively published and protected by patents, and was further exploited by industries. Since August 1992 he has been in the pharmaceutical company of Rhone-Poulenc Rorer (AVENTIS), where he was part of the academic- industrial joint unit RPR/CNRS UMR-133. He was involved in the development of novel anti-cancer peptide-mimetics and in the development of novel non-viral gene delivery complexes for gene therapy. He joined the Department of Chemistry of Bar Ilan University/Israel in 1999 as a Senior Lecturer and was promoted to Associate Professor in 2002, where he is currently associated with the Marcus Center of Pharmaceutical Chemistry. Main scientific interests: peptide, peptidomimetics, combinatorial chemistry, gene therapy and design and applications of biocompatible nanoparticles.