Structure of a Peptidoglycan-Related Polysaccharide from Providencia alcalifaciens O45

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O. G. Ovchinnikova^1,2*, B. Liu², N. A. Kocharova¹, A. S. Shashkov¹, A. N. Kondakova¹, M. Siwinska³, L. Feng^2,4, A. Rozalski⁵, L. Wang^2,4, and Y. A. Knirel¹

¹Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, 119991 Moscow, Russia; fax: (499) 137-6148; E-mail: olga.ovchinnikova@gmail.com

²TEDA School of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, China; E-mail: striker198126@yahoo.com.cn

³Department of General Microbiology, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, PL 90-237 Lodz, Poland

⁴Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, TEDA, Tianjin 300457, China

⁵Department of Immunobiology of Bacteria, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, PL 90-237 Lodz, Poland

^* To whom correspondence should be addressed.

Received February 14, 2012; Revision received February 21, 2012

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A polysaccharide was isolated from the opportunistic human pathogen Providencia alcalifaciens O45:H26 by extraction with aqueous phenol and studied by sugar and methylation analyses along with ¹H and ¹³C NMR spectroscopy, including two-dimensional ROESY and H-detected ¹H,¹³C HSQC experiments. The polysaccharide contains N-acetylglucosamine and N-acetylmuramic acid (d-GlcpNAc3Rlac) amidated with l-alanine and has the following structure:

→4)-β-d-GlcpNAc-(1→4)-β-d-GlcpNAc3(Rlac-l-Ala)-(1→.

The polysaccharide possesses a remarkable structural similarity to the bacterial cell wall peptidoglycan. It is not unique to the strain studied but is common to strains of at least four P. alcalifaciens O-serogroups (O3, O24, O38, and O45). No evidence was obtained that the polysaccharide is associated with the LPS, and hence it might represent a bacterial capsule component.

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KEY WORDS: Providencia alcalifaciens, lipopolysaccharide, N-acetylmuramic acid, structure, bacterial polysaccharide, peptidoglycan

DOI: 10.1134/S0006297912060077

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