Cicer arietinum lectin or agglutinin (CAL/CPA) is a homodimer composed of two subunits.This lectin is a glycoprotein that contains 4.5% neutral sugars and is basic in nature (pI: 9.0). It’s haemagglutination activity is inhibited by fetuin and desialylated fetuin with a carbohydrate specificity for fetuin and p-Nitrophenyl N-acetyl-α-D-galactoside. CAL possess complex-sugar specificity for N-glycans and N-acetyl-D-galactosamine, and elutes with acetyl-D-galactosamine. Although neither human or rabbit erythrocytes are agglutinated by this lectin, pronase-treated rabbit and human erythrocytes have been successfully agglutinated. None of the sugars, such as glucose, mannose or galactose, nor their derivatives, disaccharides, trisaccharides and tetrasaccharides have any effect on the agglutination of this lectin.
Texas Red is a red-fluorescent dye and when bound to Cicer arietinum Lectin (CAL/CPA) 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.