A DEVELOPMENTALLY REGULATED LECTIN IN BUFO ARENARUM EMBRYOS

ELOLA, M. T.; FINK, N. E.; HERKOVITS, J.

BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH

ASSOC BRAS DIVULG CIENTIFICA

Lugar: San Pablo; Año: 1987 vol. 20 p. 749 - 753

0100-879X

We report the levels of an endogenous beta-galactoside lectin activity from Bufo arenarum whole embryos extracts and specific inhibition by saccharides at different developmental stages. Specific activity measured against trypsinized rabbit red blood cells showed relatively high and fluctuating levels during early stages (up to about 76 h post-fertilization) which fell to significantly lower and more constant values at late stages (77-264 h post-fertilization). Lactose is the most potent inhibitor of this lectin activity, and saccharides having alpha-galactoside configurations are weaker inhibitors. At the last embryonic stage, the agglutinating activity showed a different sugar specificity which suggests either the modification of the preexistent lectin or the synthesis of another type of lectin. The possible physiological roles of these lectins in the blockage of polyspermy or in embryonic cell-cell interactions are discussed.