The structure of the cyclic enterobacterial common antigen (ECA) from Yersinia pestis

✍ Scribed by Evgeny V. Vinogradov; Yuriy A. Knirel; Jane E. Thomas-Oates; Alexander S. Shashkov; Vyacheslav L. L'vov

• Book ID: 102997679
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 607 KB
• Volume: 258
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(94)84088-1

✦ Synopsis

Two antigenic acidic polysaccharides related to enterobacterial common antigen (ECA) were isolated from a vaccine strain of a pathogenic microorganism Yersiniu pestis. The low molecular weight polysaccharide (LMP) is composed of equal amounts of 2-acetamido-2-deoxy-D-mannuronic acid, 4-acetamido-4,6-dideoxy-D-galactose (FuGINAc), and 2-amino-2-deoxy-D-glucose which is partially N-and partially 6-0-acetylated.

The structure of the trisaccharide repeating unit was established by analyses of LMP and the completely N-acetylated LMP (LMP-NAc) using 'H and 13C NMR spectroscopy, including 2D COSY and 1D NOE spectroscopy. Deamination of LMP with nitrous acid gave a set of oligomers terminated with 2,5anhydromannose and ranging from tri-to dodeca-saccharides, thus indicating a random distribution of free amino groups. FABMS analyses of LMP and LMP-NAc showed that LMP consists mainly of the cyclic tetramer of the trisaccharide repeating unit together with a small amount of the cyclic trimer and a very small amount of the cyclic pentamer and has, thus, the following structure: cycle-[ + 4)+?-o-ManpNAcA-(1 + 4)+-D-GlcpNR-(1