BenGurion University of the Negev BeerSheva Israel From Structure to Function Possible Implications of βSheet Peptides to the Origin of Life 011213 ILASOL 27 th meeting Weizmann Institute of Science ID: 1045112
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1. Boris RubinovSupervised by: Prof. Gonen AshkenasyBen-Gurion University of the Negev, Beer-Sheva, IsraelFrom Structure to Function: Possible Implications of β-Sheet Peptides to the Origin of Life01.12.13ILASOL 27th meeting – Weizmann Institute of Science
2. GoalsDesign and investigation of a new class of self - replicating peptides, based on folding into β-sheet secondary structure.01.12.13 - ILASOL2
3. 3DNAL.E. Orgel; G. von KiedrowskiRNAG. von Kiedrowski; G. F. JoyceAbiotic organic moleculesJ. Rebek; D. Philp; I.O. SutherlandPeptides – α helixM.R. Ghadri; J. Chmielewski; G. AshkenasyDadon, Z., Wagner, N., and G. Ashkenasy, Angew. Chem. Int. Ed., 2008. 47(33)01.12.13 - ILASOLMinimal Self-Replication Systems
4. 4Self-Replication by Peptidesα-Helices:Long sequences: 28-40 a.aSpecific sequences2 layers of recognitionProduct inhibitionβ-Sheet:Short sequence: 10-13 a.aSimple sequencesAssembly by H-bondsNo product inhibitionB. Rubinov, N. Wagner, H. Rapaport, and G. Ashkenasy, Angew. Chem. Int. Ed., 2009. 48.01.12.13 - ILASOL
5. Prebiotic condensation of amino acids to β-sheet peptides S.L. Miller; L.E. Orgel; A. BrackHigh structural stabilityC.M. Dobson; A. BrackSelf-propagation/replication and information transitionC.M. Dobson; C.P.J. Maury; H. MiharaEnantioselective PeptidesA. Brack; M. LahavHydrolysis/formation of oligoribonucleotidesB. Barbier, A. Brack5β-Sheet Peptides (possible implications to the Origin of Life)01.12.13 - ILASOLN. Wagner, B. Rubinov, G. Ashkenasy, ChemPhysChem, 2011, 12H. Mihara et. al., Bioorg. Med. Chem., 2004I. Weissbuch, R. A. Illos, G. Bolbach, M. Lahav, Acc. Chem. Res. 2009, 42
6. System Design – β-Sheet Peptides01.12.13 - ILASOL6Isenberg, H., K. Kjaer, and H. Rapaport, J. Am. Chem. Soc., 2006. 128(38)
7. Structural CharacterizationIn aqueous solution01.12.13 - ILASOL7AFM topography images of 1 and 2 fibrils (a and b respectively, 100 μM), formed after 30 minutes of equilibration (z scale = 4 nm)ab
8. From Structure to FunctionDesign of replication system 101.12.13 - ILASOL811
9. 9Kinetics Experiments of Replication System[E1]0=[N1]0= 250±10 µM; pH = 7; TCEP; Δ1 = [1]t – [1]001.12.13 - ILASOL116 μM41μM12μM9μM0μM~100 - foldB. Rubinov, N. Wagner, H. Rapaport, G. Ashkenasy Angew. Chem. Int. Ed., 2009. 48.
10. Full System MechanismTwo parallel processesB. Rubinov, M. Matmor, N. Wagner, O. Regev, N. Ashkenasy, G. Ashkenasy, ACS Nano 2012, 6(9)Highlighted in Nature Nanotechnology 2012, 7, 54901.12.13 - ILASOL10
11. Molecular mechanism of PRION replicationFor example: Sindi & Serio Curr. opin. Microbiol. 2009.Prions are infectious agents responsible for a variety of neurodegenerative disorders, including scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle, and new variant Creutzfeldt-Jacob disease (CJD) and kuru in humans.PrPSc = Scrapie form misfolded proteinReplication mechanismPrPc → PrPScSynthesisE + N → FPrPc + PrPScn → PrPScn+1CatalysisE + N + Fn → Fn+1PrPScn→ PrPSc1n+ PrPSc2nFragmentationFn → F1n + F2nPrPScn / PrPSc → PrPcDecayFn → NT01.12.13 - ILASOL11
12. From Structure to FunctionDesign of replication system 201.12.13 - ILASOL12
13. Epimerization & Isomerization of E201.12.13 - ILASOL13
14. 1401.12.13 - ILASOL[E-α-L]=[E-α-D]=300±10 µM; [N2]=600±10 µM; pH=7; Shaking @ 500-600 rpmKinetics Experiments of Replication SystemTemplate free reactions – Background reactions
15. 1501.12.13 - ILASOLKinetics Experiments of Replication SystemTemplate assisted reactions – Self-replication reactions[E2]=[N2]=250±10 µM; MOPS buffer (0.2 M) pH=7
16. 16Summary of β-Sheet ReplicationPeptides replication achieved using short & simple sequences.Peptide ligation (condensation of amide bond) in mild conditions (pH 7, r.t.) is plausible.The ligation reaction can be catalyzed by β-sheet structures through self-replication process.The template-assisted reaction is regio- and stereo-selective.β-Sheet structures may act as homochiral precursors in the origin of life.01.12.13 - ILASOL
17. 17AcknowledgmentsProf. Gonen AshkenasyDr. Nathaniel WagnerDr. Riky Cohen-Luria Dr. Manickasundaram SamiappanDr. Jayanta NandaZehavit DadonInbal ShumacherLina ShepelevskiSamaa AlasibiDenis IvnitskiRakesh MukherjeeChiara GlionnaNadia LevinVered ZavaroTania DronovAnne Zebitz EriksenCollaborators: Prof. Hanna Rapaport (GIXD)Dr. Vladimir VaiserDr. Shlomit MagidovichProf. Oren Regev (cryo-TEM)Dr. Einat RothEran EdriProf. Nurit Ashkenasy (AFM)Maayan MatmorDr. Yifat Miller (MD)Yoav RazTHANK YOU01.12.13 - ILASOL