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Lanthipeptides are intriguing peptides known since 1928, the year of penicillin's discovery. At that time, they were known as lantibiotics due to their (methyl)lanthionine amino acids and antibacterial activity. Their body of knowledge expanded tremendously over the last few years. Our analysis reveals that Bacteroidetes has a high state of clusters encoding the biosynthesis of class I lanthipeptides. We show that some strains of Pedobacter have a number of LanBs/genome comparable to that of some Actinobacteria. The case study selected was Pedobacter lusitanus NL19. Its clusters identified encode LanBs associated with LanCs as well as orphan LanBs. The first are concomitant with LanT transporters typical of class II lanthipeptides (and not class I), making their clusters into a hybrid class I and class II type. So far, this kind of operon was described only once and is involved in the production of pinensins, the first lanthipeptide with antifungal activity. A particular feature of pinensins is their splitted LanBs and we found that these enzymes are also widely encoded in Bacteroides. The function of a high percentage of proteins predicted to play a role in the production of Pedobacter lanthipeptides is unknown. Other major fraction of these proteins is expected to be enrolled in signal-transduction pathways. We demonstrate that the occurrence of lanthipeptides clusters in the genomes of Gram-negative bacteria is higher than previously reported. More importantly, we show that their genetic background is highly diverse, which is an undeniable foreshadowing of novel peptide structures, biochemistry and biological function., Competing Interests: Declaration of Competing Interest The author(s) declare that there are no conflicts of interest., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

[reaction in text] A new method for the synthesis of selenocysteine derivatives and selenocysteine-containing peptides is described. Fmoc-Se-p-methoxybenzylselenocysteine (1) was prepared and used for solid-phase synthesis of peptides with an N-terminal unprotected selenocysteine. Subsequent native chemical ligation with a peptide thioester provided a 17-mer that corresponds to the C-terminus of ribonucleotide reductase with selenocysteine in place of cysteine.

[reaction: see text]. Protein and peptide conjugates such as glycopeptides, prenylated peptides, and lipopeptides play essential roles in biology. A rapid and convergent entry into a variety of these compounds is described. The methodology involves the introduction of a dehydroalanine into peptides and subsequent chemoselective conjugate addition of an appropriate thiolate nucleophile, including farnesylthiolate or thioglycosides.

Useful methodology is described for the synthesis of dehydroalanine residues (II) within peptides. The unnatural amino acid (Se)-phenylselenocysteine (I) can be incorporated into growing peptide chains via standard peptide synthesis procedures. Subsequent oxidative elimination affords a dehydroalanine at the desired position. The oxidation conditions are mild and tolerate functionalities commonly found in peptides, including variously protected cysteine residues. To illustrate its utility, cyclic lanthionines have been synthesized by this method.