Conformation Analysis of GalNAc‐Appended Sugar Amino Acid Foldamers as Glycopeptide Mimics

• Published in: Chembiochem : a European journal of chemical biology Vol. 19; no. 14; pp. 1507 - 1513
• Main Authors: Sunkari, Yashoda Krishna, Pulukuri, Kiran Kumar, Kandiyal, Pancham Singh, Vaishnav, Jayanti, Ampapathi, Ravi Sankar, Chakraborty, Tushar Kanti
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 16.07.2018; Wiley Subscription Services, Inc
• Subjects: Acids; Amino acids; Antibiotics; Biochemistry & Molecular Biology; Chemistry, Medicinal; Conformation; conformation analysis; foldamers; Glycoconjugates; Glycopeptides; Hydrogen bonding; Hydrogen bonds; Life Sciences & Biomedicine; NMR; NMR spectroscopy; Nuclear magnetic resonance; Pharmacology & Pharmacy; Science & Technology; Sugar; sugar amino acids; conformation analysis; sugar amino acids; glycopeptides; O-GLYCOSYLATION; SOLID-PHASE; TERMINAL ALKYNES; UDP-GALNAC; COLON-CANCER-CELLS; PEPTIDE; foldamers; COMBINATORIAL SYNTHESIS; ALPHA-GALNAC; NMR spectroscopy; POLYPEPTIDE; TRANSFERASE
• ISSN: 1439-4227; 1439-7633
• DOI: 10.1002/cbic.201800087

Sugar amino acid (SAA)‐based foldamers with well‐defined secondary structures were appended with N‐acetylgalactosamine (GalNAc) sugars to access sequence‐defined, multidentate glycoconjugates with full control over number, spacing and position. Conformation analysis of these glycopeptides by extensive NMR spectroscopic studies revealed that the appended GalNAc units had a profound influence on the native conformational behaviour of the SAA foldamers. Whereas the 2,5‐cis glycoconjugate showed a helical structure in water, comprising of two consecutive 16‐membered hydrogen bonds, its 2,5‐trans congener displayed an unprecedented 16/10‐mixed turn structure not seen before in any glycopeptide foldamer. Icing with GalNAc sugar: Sugar amino acid (SAA)‐based foldamers with well‐defined secondary structures are appended with N‐acetylgalactosamine (GalNAc) sugars to access sequence‐defined, multidentate glycoconjugates. The GalNAc‐appended glycoconjugates nucleate in water to form an unprecedented 16/10‐mixed helical structure in a 2,5‐trans‐SAA foldamer and two 16‐membered turns in the 2,5‐cis congener.