Lectins are carbohydrate binding proteins of non-immune origin that play role in various biological processes, such as cell-cell interaction, biofilm formation or host-pathogen recognition. They differ in carbohydrate specificity as well as in affinity, which can be further increased by presence of several binding sites per lectin molecule causing so called avidity effect. Lectins are ubiquitous in nature. They were found in bacteria, plants, fungi and animals including human being. Attention is paid especially to lectins from pathogenic organisms (Pseudomonas aeruginosa, Chromobacterium violaceum, Aspergillus fumigatus, Photorhabdus asymbiotica, etc.), where they frequently assist host-pathogen recognition and take part in early stage of infection.
From the structural point of view, a few dozens of lectin folds have been already described and there is no reason to take this amount as final. An interesting group of lectins are lectins possessing 6 or 7 bladed beta-propeller fold. In this case, the blades are formed by tandem repeats, where binding sites are located in between blades. This not only allows for high affinity through multivalency effect, but also for increased variability in ligand specificity since slight variations in binding site composition is frequently observed. Structural data based on X-ray diffraction are evaluated in order to determine the real number of active binding sites and their fine specificity, as this knowledge is essential for treatment (e.g. anti-adhesive therapy) or for biotechnological applications.
This research was carried out under the project CEITEC 2020 (LQ1601) with financial support from the Ministry of Education, Youth and Sports of the Czech Republic under the National Sustainability Program II. The research received financial support from the Czech Science Foundation (GA13-25401S).