Biotechnology seminar (previously known as BE and MCB section seminar)

Speaker: Associate Professor Thomas Tørring

Title:
Unusual biosynthetic features of the triculamin-like lasso peptides

Abstract:

The triculamin-like lasso peptides are an intriguing ensemble characterized by their cationic and antibiotic properties. The natural products triculamin and alboverticillin were originally isolated from Streptomyces spp. and reported in 1958 and 1967 as potent antibiotics against M. tuberculosis.[1,2] Recently, we discovered that they are identical lasso peptides.  By comparing the genomes of the two producing strains, we revealed that the biosynthetic gene clusters (BGCs) are different from those of other lasso peptides. Both BGCs encode precursors lacking leader peptides but containing follower peptides instead. In addition, they lack the B1/B2 genes encoding the proteins responsible for recognizing and removing the leader peptides and have truncated macrocyclases. [3] By performing a bioinformatic search, we identified hundreds of BGCs encoding triculamin-like lasso peptides from several other phyla and expressed several of these in heterologous hosts.[4]Surprisingly, half of these follow canonical biosynthetic logic and contain leader peptides and B1/B2 proteins, yet yield almost identical lasso peptides. Finally, we have characterized the unusual enzymatic transformations, including a widespread resistance mechanism based on acetylation and a clostripain-like transpeptidase forming a second macrocycle between a lysine sidechain and the C-terminal carboxyl group, leading to the unique figure-of-eight structure reported for gelatinamin A and lariocidin.[4–6]

[1] K. Maeda, S. Kondo, K. Ohi, H. Kondo, E. L. Wang, Y. Osato, H. Umezawa, “A new antibiotic, alboverticillin” J Antibiot (Tokyo) 1958, 11, 30–31.

[2] S. Suzuki, K. Asahi, J. Nagatsu, Y. Kawashima, I. Suzuki, “Triculamin, a new antituberculosis substance” J Antibiot (Tokyo) 1967, 20, 126.

[3] F. D. Andersen, K. D. Pedersen, D. Wilkens Juhl, T. Mygind, P. Chopin, E. B. Svenningsen, T. B. Poulsen, M. Braad Lund, A. Schramm, C. H. Gotfredsen, T. Tørring, “Triculamin: An Unusual Lasso Peptide with Potent Antimycobacterial Activity” J. Nat. Prod. 2022, 85, 1514–1521.

[4] A. Merrild, T. Svenningsen, M. G. Chevrette, T. Tørring, “Evolution-Guided Discovery of Antimycobacterial Triculamin-Like Lasso Peptides” Angewandte Chemie International Edition 2025, 64, e202425134.

[5] M. Jangra, D. Y. Travin, E. V. Aleksandrova, M. Kaur, L. Darwish, K. Koteva, D. Klepacki, W. Wang, M. Tiffany, A. Sokaribo, B. K. Coombes, N. Vázquez-Laslop, Y. S. Polikanov, A. S. Mankin, G. D. Wright, “A broad-spectrum lasso peptide antibiotic targeting the bacterial ribosome” Nature 2025, 640, 1022–1030.

[6] T. Svenningsen, A. Merrild, F. Wang, F. D. Hansen, T. G. Johnson, R. Iwase, T. Viennet, M. K. Larsen, A. J. Link, T. Tørring, “Biosynthesis, Structure, and Antibiotic Properties of Gelatinamin A, a Triculamin‐Like Lasso Peptide” ChemBioChem 2026, 27, e70378.

Speaker: Marie Curie visiting Postdoc Ivan Rodulfo

Title:

The Journey of Apple Polyphenols: From Food Structure to Potential Health Effects

Abstract:

What happens to the beneficial compounds in an apple after we eat it? This talk will explore how the structure of the apple and its dietary fiber influence the digestion, bioaccessibility, and transformation of polyphenols, using in vitro models of the digestive process. We will follow their journey from the gastrointestinal, highlighting how digestion and microbial metabolism can modify their potential effects on health. Finally, we will consider how these interactions may contribute to communication between the gut and the brain and modulate the gut microbiota.

At the talk – no  apples, but plenty of coffee and tea. We look forward to seeing you here!