Affinity purified Pisum sativum lectin or agglutinin (PSA) is a heterodimer that consists of four subunits. It has a carbohydrate specificity towards α-linked mannose-containing oligosaccharides. It’s hemagglutinating activity can be inhibited by glucose, mannose, and sucrose. It does not have a blood group specificity. The N-terminal sequence of the lectin has shown some degree of homology compared to lectins from other legume species. Pisum sativum lectin has also shown mitogenic effect toward murine splenocytes and could inhibit activity of HIV-1 reverse transcriptase. PSA is often used to differentiate virally transformed from normal cells. Calcium and manganese ions are required for activity.
Texas Red is a red-fluorescent dye and when bound to Pisum sativum Lectin (PSA/PSL) can show the binding pattern of this lectin in cellular imaging applications. There is very little overlap between the emission spectra of Texas Red and FITC making this combination ideal for dual-labeling experiments. Rhodamine dyes, such as Texas Red, are more photostable and less sensitive to pH change when compared to other dyes such as fluorescein.