Polygonatum cyrtonema lectin (PCL) is isolated from Solomon's Seal seeds and affinity purified. This lectin is a dimer with an estimated molecular weight of 4.2 kDa and has agglutinated rabbit erythrocytes. PCL is specific to mannose/sialic acid and is one of the GNA-related lectins (formerly named the mannose binding lectin family). In the β-prism II fold of PCL exists three carbohydrate binding sites, with two sites holding the essential amino acids for recognizing mannose. The third carbohydrate binding site contains amino acid substitutions that causes PCL to have less affinity for mannose than other GNA-related lectins, but also allows for sialic acid binding. This non-mannose binding site sets PCL apart, giving it potential as an influenza A treatment that utilizes competitive binding of sialic-acid specific retrovirus infections. In cancer research, PCL has been shown to induce apoptosis via activation of the caspase-dependent, Ras-Raf, PI3K-Akt, and mitochondria-mediated p53 pathways. PCL also induces autophagic effects by blocking the same Ras-Raf and PI3K-Akt pathways that induce apoptosis, so intricate maintenance of these pathways is essential for PCL-induced cancers to progress. Pure PCL can be used for blotting and immunohistochemistry techniques. This product comes in a lyophilized form and is stable for more than three years when stored below -20°C.
Source: Polygonatum cyrtonema (Soloman's Seal)
Carbohydrate Specificity: Mannose, Sialic acid
Inhibitory Carbohydrate: Mannose, Sialic acid, Thyroglobulin
Divalent ions required: None
The lectin isolated from Polygonatum cyrtonema is a monocot mannose-binding lectin. PCL contains one active sialic acid-binding site and three mannose-binding sites but only one of the three putative mannose-binding sites is active. PCL can specifically bind to mannose, and the amino acid residues of CBSs of PCL are Gln, Asp, Asn, and Tyr, which bind to the O2, O3, and O4 of mannose through a network of hydrogen bonds. Many auxiliary interactions to stabilize binding including nonpolar van der Waals interactions. Effects of Chemical modification on hemagglutination and mitogenic activities The modification of carboxyl group residues by EDC resulted in the complete abrogation and 26% decrease in the hemagglutinating activity and mitogenic activity, respectively. Modification of Lys residues using TNBS resulted in 25% and 15% decrease in the agglutination and mitogenic activity, respectively.
Functionalized forms are available upon inquiry.