Wikipedia

Helma Wennemers

Helma B. Wennemers (born 24 June 1969 in Offenbach am Main) is a German organic chemist. She is a professor of organic chemistry at the Swiss Federal Institute of Technology in Zurich (ETH Zurich).

Helma Wennemers

Education

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Helma Wennemers studied chemistry at the Goethe University Frankfurt, completing her diploma thesis with Gerhard Quinkert [de] in 1993. She earned her PhD at Columbia University, New York in 1996, under the supervision of W. Clark Still, with a thesis "Encoded combinatorial chemistry: a tool for the study of selective intermolecular interactions." Between 1996 and 1998, she was a postdoctoral fellow at Nagoya University with Hisashi Yamamoto, before being appointed Bachem Assistant Professor at the University of Basel in 1999. She held this post until 2003, where she was promoted to associate professor. In 2011, she moved to ETH Zurich as a professor of organic chemistry.

Research

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Wennemers' research focuses on proline-rich peptides.

 
Tripeptidic catalyst of the H-Pro-Pro-Xaa type

Wennemers led the development of tripeptides containing H-Pro-Pro-Xaa type sequences (Pro: proline, Xaa: any amine) as organocatalysts for C–C bond formations based on an enamine mechanism.[1] High reactivity, stereo- and chemoselectivity for aldol[2] or conjugate addition reactions[3][4] can be achieved by varying the absolute configuration of the single amino acids as well as the functional group of the Xaa residue. The modularity of the peptides enabled creation of catalysts capable of catalyzing the conjugate addition reactions of aldehydes to nitroolefins with as little as 0.05 mol% of tripeptidic catalyst.[5]

She also worked on other organocatalyzed transformations. Inspired by natural polyketide synthases—which use malonic acid half thioesters (MAHTs) as thioester enolate equivalents — she developed organocatalytic methods for stereoselective addition reactions of MAHTs (and protected variants monothiomalonates, MTMs) to electrophiles using cinchona alkaloid derived catalysts. The introduction of fluorinated MAHTs and MTMs allowed for the stereoselective introduction of fluorine substituents in fluoroacetate aldol reactions[6] as well as further addition reactions to imines[7] and nitroolefins.[8]

In chemical biology, Wennemers uses larger proline-rich peptides, such as collagen model peptides or oligoprolines, for applications such as tumor targeting,[9] cell penetration[10] or drug delivery. She utilized Cγ-functionalized proline derivatives for the functionalization and stabilization of short-chained collagen triple helices. Further, she introduced aminoproline[11] and γ-azaproline[12] as pH-sensitive probes to tune the conformational stability of the collagen triple helix by pH change. In the field of cell penetrating peptides (CPPs), Wennemers showed that preorganization of cationic charges along an oligoproline backbone enhanced the cellular uptake of CPPs compared to more flexible oligoarginines with undefined charge display.[10] Moreover, the oligoproline-based CPPs demonstrated a defined nuclear localization and high proteolytic stability as well as low cytotoxicity.

  • Synthetic Materials:

Wennemers utilizes peptides to control the morphology of nanostructured materials for generation of ordered mesoscopic materials. She developed tripeptides for the size-controlled generation of mono-disperse, water-soluble silver-, palladium-, platinum-, and gold nanoparticles.[13] Recently, she reported peptide‐stabilized platinum nanoparticles that have greater toxicity against hepatic cancer cells (HepG2) than against other cancer cells and non‐cancerous liver cells.[14] Wennemers also explored conjugates of oligoprolines and π-conjugated systems that form hierarchical self-assemblies with diverse morphologies (e.g. nanofibers, nanorods, nanosheets). She used such a conjugate to prepare the first example of an extended triaxial supramolecular weave held together through the interplay of weak non-covalent interactions.[15]

Awards

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Wennemers work was recognized by the Leonidas Zervas Award of the European Peptide Society (2010),[16] the Pedler Award of the Royal Society of Chemistry (2016),[17] the Inhoffen Medal (2017),[18] the Netherlands Scholar Award for Supramolecular Chemistry (2019)[19] and the Arthur C. Cope Scholar Award (2020).[20]

References

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  1. ^ Wennemers, Helma (2011). "Asymmetric catalysis with peptides". Chemical Communications. 47 (44). Royal Society of Chemistry (RSC): 12036–12041. doi:10.1039/c1cc15237h. ISSN 1359-7345. PMID 21993353.
  2. ^ Krattiger, Philipp; Kovasy, Roman; Revell, Jefferson D.; Ivan, Stanislav; Wennemers, Helma (24 February 2005). "Increased Structural Complexity Leads to Higher Activity: Peptides as Efficient and Versatile Catalysts for Asymmetric Aldol Reactions". Organic Letters. 7 (6). American Chemical Society (ACS): 1101–1103. doi:10.1021/ol0500259. ISSN 1523-7060. PMID 15760149.
  3. ^ Wiesner, Markus; Revell, Jefferson D.; Wennemers, Helma (22 February 2008). "Tripeptides as Efficient Asymmetric Catalysts for 1,4-Addition Reactions of Aldehydes to Nitroolefins–A Rational Approach". Angewandte Chemie International Edition. 47 (10). Wiley: 1871–1874. doi:10.1002/anie.200704972. ISSN 1433-7851. PMID 18228232.
  4. ^ Wiesner, Markus; Neuburger, Markus; Wennemers, Helma (5 October 2009). "Tripeptides of the Type H-D-Pro-Pro-Xaa-NH2as Catalysts for Asymmetric 1,4-Addition Reactions: Structural Requirements for High Catalytic Efficiency". Chemistry – A European Journal. 15 (39). Wiley: 10103–10109. doi:10.1002/chem.200901021. ISSN 0947-6539. PMID 19697376.
  5. ^ Schnitzer, Tobias; Wennemers, Helma (18 October 2017). "Influence of the Trans/Cis Conformer Ratio on the Stereoselectivity of Peptidic Catalysts". Journal of the American Chemical Society. 139 (43). American Chemical Society (ACS): 15356–15362. doi:10.1021/jacs.7b06194. ISSN 0002-7863. PMID 29043799.
  6. ^ Saadi, Jakub; Wennemers, Helma (18 January 2016). "Enantioselective aldol reactions with masked fluoroacetates". Nature Chemistry. 8 (3). Springer Science and Business Media LLC: 276–280. Bibcode:2016NatCh...8..276S. doi:10.1038/nchem.2437. ISSN 1755-4330. PMID 26892561.
  7. ^ Cosimi, Elena; Engl, Oliver D.; Saadi, Jakub; Ebert, Marc-Olivier; Wennemers, Helma (6 October 2016). "Stereoselective Organocatalyzed Synthesis of α-Fluorinated β-Amino Thioesters and Their Application in Peptide Synthesis". Angewandte Chemie International Edition. 55 (42). Wiley: 13127–13131. doi:10.1002/anie.201607146. ISSN 1433-7851. PMID 27632946.
  8. ^ Engl, Oliver D.; Fritz, Sven P.; Käslin, Alexander; Wennemers, Helma (7 October 2014). "Organocatalytic Route to Dihydrocoumarins and Dihydroquinolinones in All Stereochemical Configurations". Organic Letters. 16 (20). American Chemical Society (ACS): 5454–5457. doi:10.1021/ol502697s. ISSN 1523-7060. PMID 25290528.
  9. ^ Kroll, Carsten; Mansi, Rosalba; Braun, Friederike; Dobitz, Stefanie; Maecke, Helmut R.; Wennemers, Helma (31 October 2013). "Hybrid Bombesin Analogues: Combining an Agonist and an Antagonist in Defined Distances for Optimized Tumor Targeting". Journal of the American Chemical Society. 135 (45). American Chemical Society (ACS): 16793–16796. doi:10.1021/ja4087648. ISSN 0002-7863. PMID 24175716.
  10. ^ a b Nagel, Yvonne A.; Raschle, Philipp S.; Wennemers, Helma (30 November 2016). "Effect of Preorganized Charge-Display on the Cell-Penetrating Properties of Cationic Peptides". Angewandte Chemie International Edition. 56 (1). Wiley: 122–126. doi:10.1002/anie.201607649. ISSN 1433-7851. PMID 27900805.
  11. ^ Siebler, Christiane; Erdmann, Roman S.; Wennemers, Helma (1 August 2014). "Switchable Proline Derivatives: Tuning the Conformational Stability of the Collagen Triple Helix by pH Changes". Angewandte Chemie International Edition. 53 (39). Wiley: 10340–10344. doi:10.1002/anie.201404935. ISSN 1433-7851. PMID 25088036.
  12. ^ Aronoff, Matthew R.; Egli, Jasmine; Menichelli, Massimiliano; Wennemers, Helma (4 March 2019). "γ‐Azaproline Confers pH Responsiveness and Functionalizability on Collagen Triple Helices". Angewandte Chemie International Edition. 58 (10). Wiley: 3143–3146. doi:10.1002/anie.201813048. ISSN 1433-7851. PMID 30633447. S2CID 58536577.
  13. ^ Corra, Stefano; Shoshan, Michal S; Wennemers, Helma (2017). "Peptide mediated formation of noble metal nanoparticles — controlling size and spatial arrangement". Current Opinion in Chemical Biology. 40. Elsevier BV: 138–144. doi:10.1016/j.cbpa.2017.09.005. ISSN 1367-5931. PMID 28961470.
  14. ^ Shoshan, Michal S.; Vonderach, Thomas; Hattendorf, Bodo; Wennemers, Helma (2019). "Peptide‐Coated Platinum Nanoparticles with Selective Toxicity against Liver Cancer Cells". Angewandte Chemie International Edition. 58 (15). Wiley: 4901–4905. doi:10.1002/anie.201813149. ISSN 1433-7851. PMID 30561882. S2CID 56169559.
  15. ^ Lewandowska, Urszula; Zajaczkowski, Wojciech; Corra, Stefano; Tanabe, Junki; Borrmann, Ruediger; Benetti, Edmondo M.; Stappert, Sebastian; Watanabe, Kohei; Ochs, Nellie A. K.; Schaeublin, Robin; Li, Chen; Yashima, Eiji; Pisula, Wojciech; Müllen, Klaus; Wennemers, Helma (24 July 2017). "A triaxial supramolecular weave". Nature Chemistry. 9 (11). Springer Science and Business Media LLC: 1068–1072. Bibcode:2017NatCh...9.1068L. doi:10.1038/nchem.2823. ISSN 1755-4330. PMID 29064493. S2CID 1248670.
  16. ^ "Helma Wennemers erhält Leonidas Zervas Award". chemie.de (in German). Retrieved 22 December 2021.
  17. ^ "Prof. Helma Wennemers erhält den Pedler Award 2016". ETH Zürich (in German). 13 May 2016. Retrieved 22 December 2021.
  18. ^ "Prof. Wennemers receives the Inhoffen Medal". Prof. Wennemers receives the Inhoffen Medal – Department of Chemistry and Applied Biosciences. 10 March 2017. Retrieved 22 December 2021.
  19. ^ "Netherlands Scholar Award for Supramolecular Chemistry goes to Prof. Helma Wennemers". Netherlands Scholar Award for Supramolecular Chemistry goes to Prof. Helma Wennemers – Department of Chemistry and Applied Biosciences. 14 January 2020. Retrieved 22 December 2021.
  20. ^ "ACS National Awards for Helma Wennemers & Peter Chen". ETH Zurich. 19 August 2020. Retrieved 22 December 2021.
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