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Updated: May 13, 2026
20:23
A Lectin HPLC Method to Enrich Selectively-glycosylated Peptides from Complex Biological Samples
Published on: October 1, 2009
LEC-2, a highly variable lectin in the lichen Peltigera membranacea.
Sheeba S Manoharan1, Vivian P W Miao, Olafur S Andrésson
1Department of Life and Environmental Sciences, University of Iceland, 101 Reykjavík, Iceland.
Symbiosis (Philadelphia, Pa.)
|March 14, 2013
Summary
The lichen lectin gene LEC-2 shows high genetic diversity and positive selection, suggesting adaptation. This adaptation is not driven by interactions with its Nostoc photobiont partner.
Area of Science:
- Mycology
- Symbiotic biology
- Molecular evolution
Background:
- Lectins are carbohydrate-binding proteins crucial for cellular interactions.
- The lichen symbiosis involves a mycobiont (fungus) and a photobiont (alga or cyanobacterium).
- LEC-2, a lectin gene, was identified in the mycobiont of the lichen Peltigera membranacea.
Purpose of the Study:
- To investigate the genetic diversity and evolutionary pressures on the LEC-2 gene in Peltigera membranacea.
- To test the hypothesis that LEC-2 evolution is driven by interactions with the Nostoc photobiont.
Main Methods:
- Sequencing of LEC-2 open reading frames from 21 individual samples.
- Analysis of nonsynonymous and synonymous nucleotide substitution rates.
- Molecular modeling of the LEC-2 protein.
- Comparison of mycobiont LEC-2 haplotypes with photobiont genotypes (rbcLX region).
Main Results:
- High polymorphism was observed in the LEC-2 protein, resulting in nine distinct haplotypes.
- Strong positive selection was detected for LEC-2, indicated by substitution rates deviating from neutrality.
- Amino acid changes were concentrated around the carbohydrate-binding pocket, suggesting altered ligand binding.
- No correlation was found between LEC-2 haplotypes and Nostoc photobiont genotypes.
Conclusions:
- The LEC-2 gene in Peltigera membranacea is under strong positive selection, indicating adaptive evolution.
- This adaptation is likely not driven by variations in the Nostoc photobiont partner.
- Further research is needed to identify the specific selective pressures on LEC-2.
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