127474-54-8Relevant articles and documents
Synthesis of nisin AB dicarba analogs using ring-closing metathesis: Influence of sp3versus sp2 hybridization of the α-carbon atom of residues dehydrobutyrine-2 and dehydroalanine-5 on the lipid II binding affinity
Slootweg, Jack C.,Van Herwerden, Eric. F.,Van Doremalen, Mark. F. M.,Breukink, Eefjan,Liskamp, Rob M. J.,Rijkers, Dirk T. S.
, p. 5997 - 6009 (2015)
Herein the synthesis of two nisin AB dicarba analogs is described, focusing on amino acid modifications at positions 2 and 5. The nisin mimics were synthesized by a combination of solid phase synthesis of the linear peptides, followed by macrocyclization via ring-closing metathesis and fragment assembly by means of solution phase chemistry. The two N-terminal nisin AB-fragment mimics contain either the native dehydrobutyrine (Dhb)/dehydroalanine (Dha) amino acid residues or alanine at position 2 and 5, respectively. The native dehydrobutyrine at position 2 and dehydroalanine at position 5 were introduced as their precursors, namely threonine and serine, respectively, and subsequent dehydration was carried out by EDCI/CuCl as the condensing agent. Both AB-fragment mimics were analyzed in a lipid II binding assay and it was found that the Ala2/Ala5 AB-mimic (2) showed a reduced activity, while the Dhb2/Dha5 AB-mimic (3) was as active as the native AB-fragment (1).
Reconstitution of peptidoglycan cross-linking leads to improved fluorescent probes of cell wall synthesis
Lebar, Matthew D.,May, Janine M.,Meeske, Alexander J.,Leiman, Sara A.,Lupoli, Tania J.,Tsukamoto, Hirokazu,Losick, Richard,Rudner, David Z.,Walker, Suzanne,Kahne, Daniel
supporting information, p. 10874 - 10877 (2014/08/18)
The peptidoglycan precursor, Lipid II, produced in the model Gram-positive bacterium Bacillus subtilis differs from Lipid II found in Gram-negative bacteria such as Escherichia coli by a single amidation on the peptide side chain. How this difference affects the cross-linking activity of penicillin-binding proteins (PBPs) that assemble peptidoglycan in cells has not been investigated because B. subtilis Lipid II was not previously available. Here we report the synthesis of B. subtilis Lipid II and its use by purified B. subtilis PBP1 and E. coli PBP1A. While enzymes from both organisms assembled B. subtilis Lipid II into glycan strands, only the B. subtilis enzyme cross-linked the strands. Furthermore, B. subtilis PBP1 catalyzed the exchange of both d-amino acids and d-amino carboxamides into nascent peptidoglycan, but the E. coli enzyme only exchanged d-amino acids. We exploited these observations to design a fluorescent d-amino carboxamide probe to label B. subtilis PG in vivo and found that this probe labels the cell wall dramatically better than existing reagents.
Enantioselective synthesis of anti-β-substituted γ,δ- unsaturated amino acids: A highly selective asymmetric thio-Claisen rearrangement
Liu, Zhihua,Qu, Hongchang,Gu, Xuyuan,Min, Byoung J.,Nyberg, Joel,Hruby, Victor J.
supporting information; experimental part, p. 4105 - 4108 (2009/05/30)
(Chemical Equation Presented) A novel synthesis of optically active anti-β-substituted γ,δ-unsaturated amino acids via a thio-Claisen rearrangement has been achieved. A 2,5-diphenylpyrrolidine was used as a (C2-symmetric chiral auxiliary to control the stereochemistry, giving good yields and excellent diastereoselectivities and enantioselectivities.
