Isolated from the cultivated banana Musa paradisiaca, banana lectin (BanLec) is a very stable mannose- and glucose-binding lectin consisting of two identical 15 kDa subunits and a reported isoelectric point of pH 7.3. Although structurally related to the Jacalin family of lectins, BanLec recognizes internal α(1,3) glucosyl- and mannosyl- residues and has also been reported to bind β(1,3) and β(1,6) glucosyl-structures.
Like Galanthus nivalis lectin, BanLec has been shown to bind gp 120 glycoprotein, an important envelope component of the human immunodeficiency virus (HIV-1), and to strongly inhibit HIV-1 entry into cells. Glycoproteins on the surface of other viruses are also likely to be recognizable by BanLec. This lectin has been reported to be a potent mitogen for peripheral T-cells in the presence of interleukin-2, and appears likely to be a cause of allergic reaction to bananas, since IgG4 antibodies against BanLec have been detected in humans.
Fluorescein labeled BanLec has an appropriate number of fluorochromes bound to provide the optimum staining characteristics for this lectin. This conjugate is supplied essentially free of unconjugated fluorochromes. The excitation maximum is at 495 nm and the emission maximum is at 515 nm.
