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Metabolic Glycoengineering of Sialic Acid Using N-acyl-modified Mannosamines
Published on: November 25, 2017
An unusual reverse turn structure adopted by a furanoid sugar amino acid incorporated in gramicidin S
Gijsbert M Grotenbreg1, Mattie S M Timmer, Antonio L Llamas-Saiz
1Leiden Institute of Chemistry, Gorlaeus Laboratories, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Abstract:
A new reverse turn, replacing one of the native type II' beta-turns in the cyclic peptide antibiotic gramicidin S, induced by a furanoid sugar amino acid is revealed. The C3-hydroxyl function plays a pivotal role by acting as a H-bond acceptor, consequently flipping the amide bond between residues i and i + 1, as was established by NMR and X-ray crystallographic analysis.
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