Purification in high yield and characterisation of the galactose-specific lectin from the seeds of snake gourd (Trichosanthes anguina).
The galactose-specific lectin present in the seeds of snake gourd (Trichosanthes anguina) was purified in high yield by affinity chromatography on cross-linked guar gum. The purified snake gourd seed lectin (SGSL) yielded a single symmetrical peak on gel filtration with an M(r) of 62 kDa and gave a single band in PAGE under non-denaturing conditions. In SDS-PAGE, SGSL gave a single band of M(r) 53 kDa in the absence of beta-mercaptoethanol, and two bands of M(r) 32 and 23 kDa in its presence, indicating that the lectin is a heterodimer in which the subunits are linked by a disulphide bridge. The lectin gave a single precipitin line in immunodiffusion experiments with antiserum raised against the purified SGSL. No cross-reactivity was found between SGSL and antiserum raised against the Momordica charantia lectin and vice versa, suggesting that the two lectins are antigenically dissimilar. Haemagglutination-inhibition data show that Me beta D-Gal is the best monosaccharide inhibitor of SGSL and indicate that an equatorial hydroxyl at C-2 and axial hydroxyl at C-4 in the pyranose form are important binding loci for the lectin.
Komath
S S
SS
School of Chemistry, University of Hyderabad, India.
Nadimpalli
S K
SK
Swamy
M J
MJ
D002846:Chromatography, Affinity; D003429:Cross Reactions; D005690:Galactose / Q000378:metabolism*; D037102:Lectins / Q000302:isolation & purification* / Q000378:metabolism; D037121:Plant Lectins; D010944:Plants; D012680:Sensitivity and Specificity
D037102:Lectins; D037121:Plant Lectins; D005690:Galactose