A molecular modeling approach to understand the structure and conformation relationship of (GlcpA)Xylan

Carbohydr Polym. 2015 Dec 10:134:175-81. doi: 10.1016/j.carbpol.2015.06.036. Epub 2015 Jun 19.

Abstract

The structure and conformation relationships of a heteropolysaccharide (GlcpA)Xylan in terms of various molecular weights, Xylp/GlcpA ratio and the distribution of GlcpA along xylan chain were investigated using computer modeling. The adiabatic contour maps of xylobiose, XylpXylp(GlcpA) and (GlcpA)XylpXylp(GlcpA) indicated that the insertion of the side group (GlcpA) influenced the accessible conformational space of xylobiose molecule. RIS-Metropolis Monte Carlo method indicated that insertion of GlcpA side chain induced a lowering effect of the calculated chain extension at low GlcpA:Xylp ratio (GlcpA:Xylp = 1:3). The chain, however, became extended when the ratio of GlcpA:Xylp above 2/3. It was also shown that the spatial extension of the polymer chains was dependent on the distribution of side chain: the random distribution demonstrated the most flexible structure compared to block and alternative distribution. The present studies provide a unique insight into the dependence of both side chain ratio and distribution on the stiffness and flexibility of various (GlcpA)Xylan molecules.

Keywords: Artemisia sphaerocephala Krasch; Computer modeling; Conformation; Polysaccharides; Xylan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Artemisia / chemistry*
  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Models, Molecular
  • Molecular Sequence Data
  • Monte Carlo Method
  • Seeds / chemistry*
  • Xylans / chemistry*

Substances

  • Xylans