3A0K: Crystal Structure Of An Antiflamatory Legume Lectin From Cymbosema Roseum Seeds

Legume lectins, despite high sequence homology, express diverse biological activities that vary in potency and efficacy. In studies reported here, the mannose-specific lectin from Cymbosema roseum (CRLI), which binds N-glycoproteins, shows both pro-inflammatory effects when administered by local injection and anti-inflammatory effects when by systemic injection. Protein sequencing was obtained by Tandem Mass Spectrometry and the crystal structure was solved by X-ray crystallography using a Synchrotron radiation source. Molecular replacement and refinement were performed using CCP4 and the carbohydrate binding properties were described by affinity assays and computational docking. Biological assays were performed in order to evaluate the lectin edematogenic activity. The crystal structure of CRLI was established to a 1.8A resolution in order to determine a structural basis for these differing activities. The structure of CRLI is closely homologous to those of other legume lectins at the monomer level and assembles into tetramers as do many of its homologues. The CRLI carbohydrate binding site was predicted by docking with a specific inhibitory trisaccharide. CRLI possesses a hydrophobic pocket for the binding of alpha-aminobutyric acid and that pocket is occupied in this structure as are the binding sites for calcium and manganese cations characteristic of legume lectins. CRLI route-dependent effects for acute inflammation are related to its carbohydrate binding domain (due to inhibition caused by the presence of alpha-methyl-mannoside), and are based on comparative analysis with ConA crystal structure. This may be due to carbohydrate binding site design, which differs at Tyr12 and Glu205 position.
PDB ID: 3A0KDownload
MMDB ID: 81196
PDB Deposition Date: 2009/3/20
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.8  Å
Source Organism:
Similar Structures:
Biological Unit for 3A0K: tetrameric; determined by author and by software (PISA)
Molecular Components in 3A0K
Label Count Molecule
Proteins (4 molecules)
Cymbosema Roseum Mannose-specific Lectin
Molecule annotation
Chemicals (10 molecules)
* Click molecule labels to explore molecular sequence information.

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