Amino Acids

, Volume 51, Issue 2, pp 219–244 | Cite as

Synthesis, 18F-labelling and radiopharmacological characterisation of the C-terminal 30mer of Clostridium perfringens enterotoxin as a potential claudin-targeting peptide

  • Reik LöserEmail author
  • Miriam Bader
  • Manuela Kuchar
  • Robert Wodtke
  • Jens Lenk
  • Johanna Wodtke
  • Konstantin Kuhne
  • Ralf Bergmann
  • Cathleen Haase-Kohn
  • Marie Urbanová
  • Jörg Steinbach
  • Jens Pietzsch
Original Article


The cell surface receptor claudin-4 (Cld-4) is upregulated in various tumours and represents an important emerging target for both diagnosis and treatment of solid tumours of epithelial origin. The C-terminal fragment of the Clostridium perfringens enterotoxin cCPE290–319 appears as a suitable ligand for targeting Cld-4. The synthesis of this 30mer peptide was attempted via several approaches, which has revealed sequential SPPS using three pseudoproline dipeptide building blocks to be the most efficient one. Labelling with fluorine-18 was achieved on solid phase using N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) and 4-[18F]fluorobenzoyl chloride as 18F-acylating agents, which was the most advantageous when [18F]SFB was reacted with the resin-bound 30mer containing an N-terminal 6-aminohexanoic spacer. Binding to Cld-4 was demonstrated via surface plasmon resonance using a protein construct containing both extracellular loops of Cld-4. In addition, cell binding experiments were performed for 18F-labelled cCPE290–319 with the Cld-4 expressing tumour cell lines HT-29 and A431 that were complemented by fluorescence microscopy studies using the corresponding fluorescein isothiocyanate-conjugated peptide. The 30mer peptide proved to be sufficiently stable in blood plasma. Studying the in vivo behaviour of 18F-labelled cCPE290–319 in healthy mice and rats by dynamic PET imaging and radiometabolite analyses has revealed that the peptide is subject to substantial liver uptake and rapid metabolic degradation in vivo, which limits its suitability as imaging probe for tumour-associated Cld-4.


Radiolabelled peptides 18F-fluorobenzoylation Difficult peptide sequences Claudin family of tight junction proteins Molecular imaging Small animal positron emission tomography 







Bovine serum albumin




2-Chlorotrityl chloride


Clostridium perfringens enterotoxin


C-terminal domain of Clostridium perfringens enterotoxin


Dulbecco’s modified Eagle’s medium






Dimethyl sulfoxide


Electron capture


Electronic circular dichroism


N,N,N′,N′-Ethylenediamine tetraacetic acids


Electrospray ionisation


Electronic supplementary material












O-(7-Azabenzotriazol‐1‐yl)‐N,N,N′,N′‐tetramethyluronium hexafluorophosphate


O-(Benzotriazol‐1‐yl)‐N,N,N′,N′‐tetramethyluronium hexafluorophosphate




High performance liquid chromatography


Injected dose


4‐Methyl benzhydrylamine




Magnetic resonance


Mass spectrometry


Phosphate-buffered saline


Photodiode array


Positron emission tomography




Post injectionem


Radioimmunoprecipitation assay


Reversed phase


Sodium dodecyl sulphate polyacrylamide gel electrophoresis


N-Succinimidyl 4-[18F]fluorobenzoate


Single photon emission computed tomography


Surface plasmon resonance


Solid-phase peptide synthesis


Tris-buffered saline




Trifluoroacetic acid






Ultra performance liquid chromatography



We wish to thank Peggy Nehring and Uta Lenkeit for assisting in peptide and radiochemical synthesis and Stefan Preusche and the cyclotron team for providing [18F]fluoride. We highly appreciate the support of Catharina Knöfel, Aline Morgenegg and Mareike Barth in the cell-based and immunohistochemical experiments. Furthermore, we are grateful to Andrea Suhr and Regina Herrlich for skilful assistance in the animal experiments. RL is grateful for partial financial support by the Fonds der Chemischen Industrie. The authors thank the Helmholtz Association for funding a part of this work through the Helmholtz Cross-Programme Initiative “Technology and Medicine—Adaptive Systems”.

Compliance with ethical standards

Conflict of interest

The authors have no conflict of interest to declare.

Ethical approval

The animal experiments were performed in accordance to the guidelines of the German Regulations of Animal Welfare. The protocol was approved by the local Ethical Committee for Animal Experiments (Reference Numbers 24D-9168.11-4/2007-2 and 24-9168.21-4/2004-1).

Supplementary material

726_2018_2657_MOESM1_ESM.pdf (1.9 mb)
Supplementary material 1 (PDF 1924 kb)


  1. Boireau S, Buchert M, Samuel MS, Pannequin J, Ryan JL, Choquet A, Chapuis H, Rebillard X, Avances C, Ernst M, Joubert D, Mottet N, Hollande F (2007) DNA-methylation-dependent alterations of claudin-4 expression in human bladder carcinoma. Carcinogenesis 28:246–258. CrossRefPubMedGoogle Scholar
  2. Bollhagen R, Schmiedberger M, Barlos K, Grell E (1994) A new reagent for the cleavage of fully protected peptides synthesized on 2-chlorotrityl chloride resin. J Chem Soc Chem Commun. CrossRefGoogle Scholar
  3. Cocco E, Casagrande F, Bellone S, Richter CE, Bellone M, Todeschini P, Holmberg JC, Fu HH, Montagna MK, Mor G, Schwartz PE, Arin-Silasi D, Azoudi M, Rutherford TJ, Abu-Khalaf M, Pecorelli S, Santin AD (2010) Clostridium perfringens enterotoxin carboxy-terminal fragment is a novel tumor-homing peptide for human ovarian cancer. BMC Cancer 10:349. CrossRefPubMedPubMedCentralGoogle Scholar
  4. de Mol NJ, Dekker FJ, Broutin I, Fischer MJE, Liskamp RMJ (2005) Surface plasmon resonance thermodynamic and kinetic analysis as a strategic tool in drug design. Distinct ways for phosphopeptides to plug into Src- and Grb2 SH2 domains. J Med Chem 48:753–763. CrossRefPubMedGoogle Scholar
  5. Ding L, Lu Z, Lu Q, Chen YH (2013) The claudin family of proteins in human malignancy: a clinical perspective. Cancer Manag Res 5:367–375. PubMedPubMedCentralCrossRefGoogle Scholar
  6. Echalier C, Al-Halifa S, Kreiter A, Enjalbal C, Sanchez P, Ronga L, Puget K, Verdie P, Amblard M, Martinez J, Subra G (2013) Heating and microwave assisted SPPS of C-terminal acid peptides on trityl resin: the truth behind the yield. Amino Acids 45:1395–1403. CrossRefPubMedGoogle Scholar
  7. Fani M, Maecke HR (2012) Radiopharmaceutical development of radiolabelled peptides. Eur J Nucl Med Mol Imaging 39(Suppl 1):S11–S30. CrossRefPubMedGoogle Scholar
  8. Feni L, Omrane MA, Fischer M, Zlatopolskiy BD, Neumaier B, Neundorf I (2017) Convenient preparation of 18F-labeled peptide probes for potential claudin-4 PET imaging. Pharmaceuticals 10:99. CrossRefPubMedCentralGoogle Scholar
  9. Friligou I, Papadimitriou E, Gatos D, Matsoukas J, Tselios T (2011) Microwave-assisted solid-phase peptide synthesis of the 60–110 domain of human pleiotrophin on 2-chlorotrityl resin. Amino Acids 40:1431–1440. CrossRefPubMedGoogle Scholar
  10. Fujita K, Katahira J, Horiguchi Y, Sonoda N, Furuse M, Tsukita S (2000) Clostridium perfringens enterotoxin binds to the second extracellular loop of claudin-3, a tight junction integral membrane protein. FEBS Lett 476:258–261. CrossRefPubMedGoogle Scholar
  11. Goodman M, Stueben KC (1962) Peptide synthesis via amino acid active esters. II. Some abnormal reactions during peptide synthesis. J Am Chem Soc 84:1279–1283. CrossRefGoogle Scholar
  12. Hanna PC, Mietzner TA, Schoolnik GK, McClane BA (1991) Localization of the receptor-binding region of clostridium perfringens enterotoxin utilizing cloned toxin fragments and synthetic peptides. The 30 C-terminal amino acids define a functional binding region. J Biol Chem 266:11037–11043PubMedGoogle Scholar
  13. Hanna PC, Wnek AP, McClane B (1995) Molecular cloning of the 3′ half of the Clostridium perfringens enterotoxin gene and demonstration that this region encodes receptor-binding activity. J Bacteriol 171:6815–6820CrossRefGoogle Scholar
  14. Harada M, Kondoh M, Ebihara C, Takahashi A, Komiya E, Fujii M, Mizuguchi H, Tsunoda S, Horiguchi Y, Yagi K, Watanabe Y (2007) Role of tyrosine residues in modulation of claudin-4 by the C-terminal fragment of Clostridium perfringens enterotoxin. Biochem Pharmacol 73:206–214. CrossRefPubMedGoogle Scholar
  15. Harris PWR, Kowalczyk R, Hay DL, Brimble MA (2012) A single pseudoproline and microwave solid phase peptide synthesis facilitates an efficient synthesis of human amylin 1–37. Int J Pept Res Ther 19:147–155. CrossRefGoogle Scholar
  16. Heinlein C, Varon Silva D, Troster A, Schmidt J, Gross A, Unverzagt C (2011) Fragment condensation of C-terminal pseudoproline peptides without racemization on the solid phase. Angew Chem Int Ed Engl 50:6406–6410. CrossRefPubMedGoogle Scholar
  17. Hess E, Takacs S, Scholten B, Tarkanyi F, Coenen HH, Qaim SM (2001) Excitation function of the 18O(p,n)18F nuclear reaction from threshold up to 30 MeV. Radiochim Acta 89:357–362. CrossRefGoogle Scholar
  18. Hosseinimehr SJ, Tolmachev V, Orlova A (2012) Liver uptake of radiolabeled targeting proteins and peptides: considerations for targeting peptide conjugate design. Drug Discov Today 17:1224–1232. CrossRefPubMedGoogle Scholar
  19. Ivanov AI, Nusrat A, Parkos CA (2004) Endocytosis of epithelial apical junctional proteins by a clathrin-mediated pathway into a unique storage compartment. Mol Biol Cell 15:176–188. CrossRefPubMedPubMedCentralGoogle Scholar
  20. Jayaraman G, Kumar TKS, Arunkumar AI, Yu C (1996) 2,2,2-Trifluoroethanol induces helical conformation in an all β-sheet protein. Biochem Biophys Res Commun 222:33–37CrossRefPubMedGoogle Scholar
  21. Jullian M, Hernandez A, Maurras A, Puget K, Amblard M, Martinez J, Subra G (2009) N terminus FITC labeling of peptides on solid support: the truth behind the spacer. Tetrahedron Lett 50:260–263. CrossRefGoogle Scholar
  22. Juul SM, Jones RH, Evans JL, Neffe J, Sönksen PH, Brandenburg D (1986) Evidence for an early degradative event to the insulin molecule following binding to hepatocyte receptors. Biochim Biophys Acta 856:310–319. CrossRefPubMedGoogle Scholar
  23. Kapty J, Kniess T, Wuest F, Mercer JR (2011) Radiolabeling of phosphatidylserine-binding peptides with prosthetic groups N-[6-(4-[18F]fluorobenzylidene)aminooxyhexyl]maleimide ([18F]FBAM) and N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB). Appl Radiat Isot 69:1218–1225. CrossRefPubMedGoogle Scholar
  24. Kiesewetter DO, Eckelman WC (2001) Radiochemical synthesis of [18F]fluoropaclitexel ([18F]FPAC). J Label Compd Radiopharm 44:S903–S905CrossRefGoogle Scholar
  25. Kim DH, Blacker M, Valliant JF (2014) Preparation and evaluation of fluorine-18-labeled insulin as a molecular imaging probe for studying insulin receptor expression in tumors. J Med Chem 57:3678–3686. CrossRefPubMedGoogle Scholar
  26. Kimura J, Abe H, Kamitani S, Toshima H, Fukui A, Miyake M, Kamata Y, Sugita-Konishi Y, Yamamoto S, Horiguchi Y (2010) Clostridium perfringens enterotoxin interacts with claudins via electrostatic attraction. J Biol Chem 285:401–408. CrossRefPubMedGoogle Scholar
  27. Kominsky SL, Tyler B, Sosnowski J, Brady K, Doucet M, Nell D, Smedley JG 3rd, McClane B, Brem H, Sukumar S (2007) Clostridium perfringens enterotoxin as a novel-targeted therapeutic for brain metastasis. Cancer Res 67:7977–7982. CrossRefPubMedGoogle Scholar
  28. Kuchar M, Pretze M, Kniess T, Steinbach J, Pietzsch J, Löser R (2012) Site-selective radiolabeling of peptides by 18F-fluorobenzoylation with [18F]SFB in solution and on solid phase: a comparative study. Amino Acids 43:1431–1443. CrossRefPubMedGoogle Scholar
  29. Kuchar M, Neuber C, Belter B, Bergmann R, Lenk J, Wodtke R, Kniess T, Steinbach J, Pietzsch J, Löser R (2018) Evaluation of fluorine-18-labelled α1(I)-N-telopeptide analogs as substrate-based radiotracers for PET imaging of melanoma-associated lysyl oxidase. Front Chem. PubMedPubMedCentralCrossRefGoogle Scholar
  30. Kwon MJ (2013) Emerging roles of claudins in human cancer. Int J Mol Sci 14:18148–18180. CrossRefPubMedPubMedCentralGoogle Scholar
  31. Lang L, Jagoda E, Schmall B, Vuong B-K, Adams HR, Nelson DL, Carson RE, Eckelman WC (1999) Development of fluorine-18-labeled 5-HT1A antagonists. J Med Chem 42:1576–1586. CrossRefPubMedGoogle Scholar
  32. Ling J, Liao H, Clark R, Wong MS, Lo DD (2008) Structural constraints for the binding of short peptides to claudin-4 revealed by surface plasmon resonance. J Biol Chem 283:30585–30595. CrossRefPubMedPubMedCentralGoogle Scholar
  33. London N, Movshovitz-Attias D, Schueler-Furman O (2010) The structural basis of peptide-protein binding strategies. Structure 18:188–199. CrossRefPubMedGoogle Scholar
  34. Madala PK, Tyndall JD, Nall T, Fairlie DP (2010) Update 1 of: proteases universally recognize beta strands in their active sites. Chem Rev 110:PR1–PR31. CrossRefPubMedGoogle Scholar
  35. Mäding P, Füchtner F, Wüst F (2005) Module-assisted synthesis of the bifunctional labelling agent N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB). Appl Radiat Isot 63:329–332. CrossRefPubMedGoogle Scholar
  36. Mamat C, Mosch B, Neuber C, Köckerling M, Bergmann R, Pietzsch J (2012) Fluorine-18 radiolabeling and radiopharmacological characterization of a benzodioxolylpyrimidine-based radiotracer targeting the receptor tyrosine kinase EphB4. ChemMedChem 7:1991–2003. CrossRefPubMedGoogle Scholar
  37. Maynard AJ, Sharman GJ, Searle MS (1998) Origin of β-hairpin stability in solution: structural and thermodynamic analysis of the folding of a model peptide supports hydrophobic stabilization in water. J Am Chem Soc 120:1996–2007CrossRefGoogle Scholar
  38. Mitchell LA, Koval M (2010) Specificity of interaction between Clostridium perfringens enterotoxin and claudin-family tight junction proteins. Toxins 2:1595–1611. CrossRefPubMedPubMedCentralGoogle Scholar
  39. Mosley M, Knight J, Neesse A, Michl P, Iezzi M, Kersemans V, Cornelissen B (2015) Claudin-4 SPECT Imaging allows detection of aplastic lesions in a mouse model of breast cancer. J Nucl Med 56:745–751. CrossRefPubMedGoogle Scholar
  40. Mutter M (2013) Four decades, four places and four concepts. Chimia (Aarau) 67:868–873. CrossRefGoogle Scholar
  41. Neesse A, Griesmann H, Gress TM, Michl P (2012) Claudin-4 as therapeutic target in cancer. Arch Biochem Biophys 524:64–70. CrossRefPubMedGoogle Scholar
  42. Neesse A, Hahnenkamp A, Griesmann H, Buchholz M, Hahn SA, Maghnouj A, Fendrich V, Ring J, Sipos B, Tuveson DA, Bremer C, Gress TM, Michl P (2013) Claudin-4-targeted optical imaging detects pancreatic cancer and its precursor lesions. Gut 62:1034–1043. CrossRefPubMedGoogle Scholar
  43. Osanai M, Takasawa A, Murata M, Sawada N (2017) Claudins in cancer: bench to bedside. Pflügers Arch Eur J Physiol 469:55–67. CrossRefGoogle Scholar
  44. Paradis-Bas M, Tulla-Puche J, Albericio F (2016) The road to the synthesis of “difficult peptides”. Chem Soc Rev 45:631–654. CrossRefPubMedGoogle Scholar
  45. Pietzsch J, Bergmann R, Wuest F, Pawelke B, Hultsch C, van den Hoff J (2005) Catabolism of native and oxidized low density lipoproteins: in vivo insights from small animal positron emission tomography studies. Amino Acids 29:389–404. CrossRefPubMedGoogle Scholar
  46. Piontek A, Rossa J, Protze J, Wolburg H, Hempel C, Günzel D, Krause G, Piontek J (2017a) Polar and charged extracellular residues conserved among barrier-forming claudins contribute to tight junction strand formation. Ann N Y Acad Sci 1397:143–156. CrossRefPubMedGoogle Scholar
  47. Piontek A, Witte C, May Rose H, Eichner M, Protze J, Krause G, Piontek J, Schröder L (2017b) A cCPE-based xenon biosensor for magnetic resonance imaging of claudin-expressing cells. Ann N Y Acad Sci 1397:195–208. CrossRefPubMedGoogle Scholar
  48. Protze J, Eichner M, Piontek A, Dinter S, Rossa J, Blecharz KG, Vajkoczy P, Piontek J, Krause G (2015) Directed structural modification of Clostridium perfringens enterotoxin to enhance binding to claudin-5. Cell Mol Life Sci 72:1417–1432. CrossRefPubMedGoogle Scholar
  49. Reiersen H, Rees AR (2000) Trifluoroethanol may form a solvent matrix for assisted hydrophobic interactions between peptide side chains. Protein Eng 13:739–743. CrossRefPubMedGoogle Scholar
  50. Rhodes CA, Pei D (2017) Bicyclic peptides as next-generation therapeutics. Chem Eur J 23:12690–12703. CrossRefPubMedGoogle Scholar
  51. Richter S, Wuest F (2014) 18F-labeled peptides: the future is bright. Molecules 19:20536–20556. CrossRefPubMedPubMedCentralGoogle Scholar
  52. Salvador E, Burek M, Förster CY (2016) Tight junctions and the tumor microenvironment. Curr Pathobiol Rep 4:135–145. CrossRefPubMedPubMedCentralGoogle Scholar
  53. Šebestik J, Zawada Z, Šafařik M, Hlavaček J (2012) Comparative syntheses of peptides and peptide thioesters derived from mouse and human prion proteins. Amino Acids 43:1297–1309. CrossRefPubMedGoogle Scholar
  54. Seimbille Y, Czernin J, Phelps ME, Silverman DHS (2005) Synthesis of an 18F-fluorobenzoate idarubicin derivative as new potential PET radiotracer to predict chemotherapy resistance. J Label Compd Radiopharm 48:819–827. CrossRefGoogle Scholar
  55. Seitz R, König H, Dodt J (2006) Blood. In: Elvers B (ed) Ullmann’s encyclopedia of industrial chemistry. Wiley-VCH, Weinheim. CrossRefGoogle Scholar
  56. Shinoda T, Shinya N, Ito K, Ishizuka-Katsura Y, Ohsawa N, Terada T, Hirata K, Kawano Y, Yamamoto M, Tomita T, Ishibashi Y, Hirabayashi Y, Kimura-Someya T, Shirouzu M, Yokoyama S (2016a) Cell-free methods to produce structurally intact mammalian membrane proteins. Sci Rep 6:30442. CrossRefPubMedPubMedCentralGoogle Scholar
  57. Shinoda T, Shinya N, Ito K, Ohsawa N, Terada T, Hirata K, Kawano Y, Yamamoto M, Kimura-Someya T, Yokoyama S, Shirouzu M (2016b) Structural basis for disruption of claudin assembly in tight junctions by an enterotoxin. Sci Rep 6:33632. CrossRefPubMedPubMedCentralGoogle Scholar
  58. Singh AB, Dhawan P (2015) Claudins and cancer: fall of the soldiers entrusted to protect the gate and keep the barrier intact. Semin Cell Dev Biol 42:58–65. CrossRefPubMedGoogle Scholar
  59. Sodoyez J, Sodoyez-Goffaux F, Guillaume M, Merchie G (1983) [123I]Insulin metabolism in normal rats and humans: external detection by a scintillation camera. Science 219:865–867. CrossRefPubMedGoogle Scholar
  60. Sodoyez JC, Sodoyez Goffaux F, von Frenckell R, De Vos CJ, Treves S, Kahn CR (1985) Differing effects of antiinsulin serum and antiinsulin receptor serum on 123I-insulin metabolism in rats. J Clin Invest 75:1455–1462. CrossRefPubMedPubMedCentralGoogle Scholar
  61. Suzuki H, Kondoh M, Li X, Takahashi A, Matsuhisa K, Matsushita K, Kakamu Y, Yamane S, Kodaka M, Isoda K, Yagi K (2011) A toxicological evaluation of a claudin modulator, the C-terminal fragment of Clostridium perfringens enterotoxin, in mice. Pharmazie 66:543–546. PubMedCrossRefGoogle Scholar
  62. Takahashi A, Komiya E, Kakutani H, Yoshida T, Fujii M, Horiguchi Y, Mizuguchi H, Tsutsumi Y, Tsunoda S, Koizumi N, Isoda K, Yagi K, Watanabe Y, Kondoh M (2008) Domain mapping of a claudin-4 modulator, the C-terminal region of C-terminal fragment of Clostridium perfringens enterotoxin, by site-directed mutagenesis. Biochem Pharmacol 75:1639–1648. CrossRefPubMedGoogle Scholar
  63. Takahashi A, Kondoh M, Suzuki H, Watari A, Yagi K (2012) Pathological changes in tight junctions and potential applications into therapies. Drug Discov Today 17:727–732. CrossRefPubMedGoogle Scholar
  64. Tickler AK, Wade JD (2007) Overview of solid phase synthesis of “difficult peptide” sequences. Curr Protoc Protein Sci. (Chapter 18:Unit 18 18) PubMedCrossRefGoogle Scholar
  65. Tondera C, Laube M, Pietzsch J (2017) Insights into binding of S100 proteins to scavenger receptors: class B scavenger receptor CD36 binds S100A12 with high affinity. Amino Acids 49:183–191. CrossRefPubMedGoogle Scholar
  66. Tsujiwaki M, Murata M, Takasawa A, Hiratsuka Y, Fukuda R, Sugimoto K, Ono Y, Nojima M, Tanaka S, Hirata K, Kojima T, Sawada N (2015) Aberrant expression of claudin-4 and -7 in hepatocytes in the cirrhotic human liver. Med Mol Morphol 48:33–43. CrossRefPubMedGoogle Scholar
  67. Tuchscherer G, Mutter M (2003) Template-Assembled Synthetic Proteins. In: Goodman M, Felix A, Moroder L, Toniolo C (eds) Houben-Weyl methods of organic chemistry, vol E22d. G. Thieme, Stuttgart, pp 6–64Google Scholar
  68. Tummino PJ, Copeland RA (2008) Residence time of receptor-ligand complexes and its effect on biological function. Biochemistry 47:5481–5492. CrossRefPubMedGoogle Scholar
  69. Tyndall JD, Nall T, Fairlie DP (2005) Proteases universally recognize beta strands in their active sites. Chem Rev 105:973–999. CrossRefPubMedGoogle Scholar
  70. Ullrich M, Bergmann R, Peitzsch M, Zenker EF, Cartellieri M, Bachmann M, Ehrhart-Bornstein M, Block NL, Schally AV, Eisenhofer G, Bornstein SR, Pietzsch J, Ziegler CG (2016) Multimodal somatostatin receptor theranostics using [64Cu]Cu-/[177Lu]Lu-DOTA-(Tyr(3))octreotate and AN-238 in a mouse pheochromocytoma model. Theranostics 6:650–665. CrossRefPubMedPubMedCentralGoogle Scholar
  71. Urbanova M, Maloň P (2012) Circular dichroism spectroscopy. In: Schalley C (ed) Analytical methods in supramolecular chemistry, 2nd edn. Wiley-VCH, Weinheim, pp 337–369CrossRefGoogle Scholar
  72. van der Born D, Pees A, Poot AJ, Orru RVA, Windhorst AD, Vugts DJ (2017) Fluorine-18 labelled building blocks for PET tracer synthesis. Chem Soc Rev 46:4709–4773. CrossRefPubMedGoogle Scholar
  73. Van Itallie CM, Betts L, Smedley JG 3rd, McClane BA, Anderson JM (2008) Structure of the claudin-binding domain of Clostridium perfringens enterotoxin. J Biol Chem 283:268–274. CrossRefPubMedGoogle Scholar
  74. Vernieri E, Valle J, Andreu D, de la Torre BG (2014) An optimized Fmoc synthesis of human defensin 5. Amino Acids 46:395–400. CrossRefPubMedGoogle Scholar
  75. Veshnyakova A, Protze J, Rossa J, Blasig IE, Krause G, Piontek J (2010) On the interaction of Clostridium perfringens enterotoxin with claudins. Toxins 2:1336–1356. CrossRefPubMedPubMedCentralGoogle Scholar
  76. White P, Keyte JW, Bailey K, Bloomberg G (2004) Expediting the Fmoc solid phase synthesis of long peptides through the application of dimethyloxazolidine dipeptides. J Pept Sci 10:18–26. CrossRefPubMedGoogle Scholar
  77. Winkler DFH, Tian K (2015) Investigation of the automated solid-phase synthesis of a 38mer peptide with difficult sequence pattern under different synthesis strategies. Amino Acids 47:787–794. CrossRefPubMedGoogle Scholar
  78. Wodtke R, Ruiz-Gomez G, Kuchar M, Pisabarro MT, Novotna P, Urbanova M, Steinbach J, Pietzsch J, Löser R (2015) Cyclopeptides containing the DEKS motif as conformationally restricted collagen telopeptide analogues: synthesis and conformational analysis. Org Biomol Chem 13:1878–1896. CrossRefPubMedGoogle Scholar
  79. Wojczewski C, Schwarzer K, Engels JW (2000) Synthesis of 3′-thioamido-modified 3′-deoxythymidine 5′-triphosphates by regioselective thionation and their use as chain terminators in DNA sequencing. Helv Chim Acta 83:1268–1277CrossRefGoogle Scholar
  80. Wolf S, Haase-Kohn C, Lenk J, Hoppmann S, Bergmann R, Steinbach J, Pietzsch J (2011) Expression, purification and fluorine-18 radiolabeling of recombinant S100A4: a potential probe for molecular imaging of receptor for advanced glycation endproducts in vivo? Amino Acids 41:809–820. CrossRefPubMedGoogle Scholar
  81. Woody R (2002) Circular Dichroism. In: Goodman M, Felix A, Moroder L, Toniolo C (eds) Houben-Weyl methods of organic chemistry, vol E22b. Synthesis of peptides. Georg Thieme Verlag, StuttgartGoogle Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2018

Authors and Affiliations

  • Reik Löser
    • 1
    • 2
    Email author
  • Miriam Bader
    • 1
    • 2
  • Manuela Kuchar
    • 1
    • 2
  • Robert Wodtke
    • 1
    • 2
  • Jens Lenk
    • 1
    • 2
  • Johanna Wodtke
    • 1
  • Konstantin Kuhne
    • 1
    • 2
  • Ralf Bergmann
    • 1
  • Cathleen Haase-Kohn
    • 1
  • Marie Urbanová
    • 3
  • Jörg Steinbach
    • 1
    • 2
  • Jens Pietzsch
    • 1
    • 2
  1. 1.Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden RossendorfDresdenGermany
  2. 2.Faculty of Chemistry and Food Chemistry, School of ScienceTechnische Universität DresdenDresdenGermany
  3. 3.Department of Physics and MeasurementsUniversity of Chemistry and TechnologyPragueCzech Republic

Personalised recommendations