INHIBITION OF THE GROWTH OF CALCIUM-CARBONATE CRYSTALS BY MULTIPLE LECTINS IN THE CELOMIC FLUID OF THE ACORN BARNACLE MEGABALANUS-ROSA

The interaction between the multiple lectins (BRA-5 BRA-3) in the coelomic fluid of the acorn barnacle Megabalanus rosa and calcium ions was studied by ultraviolet difference spectroscopy. The association constants for BRA-2 and BRA-3 were 1.4 x 10(4) M(-1) and 2.2 x 10(4)M(-1) at pH 8.0, respectively. Multiple lectins inhibited the crystal growth of supersaturated calcium carbonate solution at a lectin concentration of > 0.1 mg/30 ml. Destruction of the carbohydrate-recognition domains of the lectins decreased the inhibitory activities on the crystal growth. Incorporation of BRAs into the crystal was demonstrated using FITC-labeled lectins.