Glycoconjugate Journal

, Volume 12, Issue 2, pp 109–112 | Cite as

Streptococcal glucan-binding lectins do not recognize methylated α-1,6 glucans

  • Jing Wang
  • Sujan Singh
  • K. G. Taylor
  • R. J. Doyle
Short Communication


The glucan-binding lectin (GBL) ofStreptococcus sobrinus is cell associated, enabling the bacteria to be aggregated by α-1,6 glucans. Glucans, such as amylose, pullulan, laminarin and nigeran, have no affinity for the lectin. High molecular weight α-1,6 glucans (dextrans) readily aggregate the bacteria, whereas low molecular weight glucans inhibit the aggregation brought about by the high molecular weight species. Methylated glucan T-2000 (an α-1,6 glucan with an average molecular weight of 2 × 106 Da) aggregated the bacteria very poorly when the extent of methylation (DS, or degree of substitution) was high, and less poorly when the DS was low. Similarly, methylated low molecular weight α-1,6 glucan was a poor inhibitor of aggregation induced by the high molecular weight glucan T-2000. Because the methylation occurred primarily on the hydroxyl of C-2, it is suggested that the hydroxyl is needed for formation of the lectin-glucan complex. It appears that the GBL is not only stereospecific in interaction with glucans, but also regiospecific, interacting only with the underivatized α-1,6-glucan.


Glucan lectin methylation 


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Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • Jing Wang
    • 1
  • Sujan Singh
    • 2
  • K. G. Taylor
    • 2
  • R. J. Doyle
    • 1
  1. 1.Department of MicrobiologyUniversity of LouisvilleLouisvilleUSA
  2. 2.Department of ChemistryUniversity of LouisvilleLouisvilleUSA

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