Surugamides A–E, Cyclic Octapeptides with Four d-Amino Acid Residues, from a Marine Streptomyces sp.: LC–MS-Aided Inspection of Partial Hydrolysates for the Distinction of d- and l-Amino Acid Residues in the Sequence
摘要:
Surugamides A-E (1-5), cyclic octapeptides with four D-amino acid residues, were isolated from the broth of marine-derived Streptomyces sp. Their planar structures were determined by analyses of spectroscopic data, and the absolute configuration of constituent amino acid residues was determined by the Marfey's method. Differentiation of D-Ile and L-Ile in the sequence was established by chiral analysis of fragment peptides obtained from the partial hydrolysate, whose identification was conducted by LC-MS/MS.
Surugamides A–E, Cyclic Octapeptides with Four <scp>d</scp>-Amino Acid Residues, from a Marine Streptomyces sp.: LC–MS-Aided Inspection of Partial Hydrolysates for the Distinction of <scp>d</scp>- and <scp>l</scp>-Amino Acid Residues in the Sequence
Surugamides A-E (1-5), cyclic octapeptides with four D-amino acid residues, were isolated from the broth of marine-derived Streptomyces sp. Their planar structures were determined by analyses of spectroscopic data, and the absolute configuration of constituent amino acid residues was determined by the Marfey's method. Differentiation of D-Ile and L-Ile in the sequence was established by chiral analysis of fragment peptides obtained from the partial hydrolysate, whose identification was conducted by LC-MS/MS.
The N-terminal substrate specificity of the SurE peptide cyclase
作者:Asif Fazal、Jake Wheeler、Michael E. Webb、Ryan F. Seipke
DOI:10.1039/d2ob01061e
日期:——
SurE is a standalone peptidecyclase essential for the production of surugamide antibiotics. Although SurE catalyses the cyclisation of varied nonribosomalpeptides in vivo, its substrate specificity is poorly understood. To address this issue, an on-resin SurE cyclisation assay was developed and in combination with SNAC thioesters and kinetic measurements was used to define the chemical space of the