TY  - JOUR
A1  - Lamping, Matthias
A1  - Enck, Sebastian
A1  - Geyer, Armin
T1  - Inverse γ-Turn-Inspired Peptide: Synthesis and Analysis of Segetalin A Indole Hemiaminal
JF  - European Journal of Organic Chemistry
N2  - Substitution of a peptide bond for an imine transforms the irreversible macrocyclization of peptides into a reversible process. The inherent cyclization tendency of a linear peptide is then analyzable through the equilibrium between the aldehyde and the imine by virtue of the higher reactivity of the corresponding linear peptide aldehyde. The tryptophan side chain of segetalin A aldehyde forms a 12‐membered cyclic indole hemiaminal instead of the 18‐membered macrocyclic imine expected. Herein, we analyzed this uncommon hemiaminal that shows that the biosynthesis of cyclic peptides is not necessarily based on linear precursor peptides with a high inherent macrolactamization tendency.
KW  - Peptides
KW  - Aldehydes
KW  - Cyclization
KW  - Macrocycles
KW  - Nitrogen heterocycles
Y1  - 2015
U6  - http://dx.doi.org/10.1002/ejoc.201501179
SN  - 1099-0690
VL  - 2015
IS  - 34
SP  - 7443
EP  - 7448
ER  - 
TY  - JOUR
A1  - Fischer, Sabrina
A1  - Lamping, Matthias
A1  - Gold, Maike
A1  - Röttger, Yvonne
A1  - Brödje, Dörte
A1  - Dodel, Richard
A1  - Frantz, Renate
A1  - Mraheil, Mobarak Abu
A1  - Chakraborty, Trinad
A1  - Geyer, Armin
T1  - Synthesis of a biological active β-hairpin peptide by addition of two structural motifs
JF  - Bioorganic & Medicinal Chemistry
N2  - The idea of privileged scaffolds – that there seem to be more bioactive compounds found around some structures than others – is well established for small drug molecules, but has little significance for standalone peptide secondary structures whose adaptable shapes escape the definition of a 3D motif in the absence of a protein scaffold. Here, we joined two independent biological functions in a single highly restricted peptide to support the hypothesis that the β-hairpin shape is the common basis of two otherwise unrelated biological recognition processes. To achieve this, the hydrophobic cluster HWX4LV from the decapeptide cyclic hairpin model peptide C1-C10 cyclo-CHWEGNKLVC was included in the bicyclic peptide 2. The designed β-hairpin peptide C4-C17, C8-C13 bicyclo-KHQCHWECTZGRCRLVCGRSGS (2, Z = citrulline), serves, on the one hand, as a specific epitope for rheumatoid autoantibodies and, on the other hand, shows a not negligible antibiotic effect against the bacterial strain E. coli AS19.
KW  - Peptides
KW  - Disulfides
KW  - NMR spectroscopy
KW  - Filaggrin
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.bmc.2016.11.022
SN  - 0968-0896
VL  - 25
IS  - 2
SP  - 603
EP  - 608
ER  -