IMPACT OF ALUMINUM, FLUORIDE AND FLUOROALUMINATE COMPLEX ON ATPASE ACTIVITY OF NOSTOC LINCKIA AND CHLORELLA-VULGARIS

This study demonstrates a pH-dependent inhibition of Mg2+- and Ca2+-AT Pase activities of Nostoc linckia and Chlorella vulgaris exposed to Al Cl3, AlF3, NaF and AlCl3 + NaF together. ALF(3) and the combination of AlCl3 + NaF were more inhibitory to both the enzymes as compared with AlCl3 and NaF. Toxicity of the test compounds increased with increasi ng acidity, Interaction of AlCl3 + NaF was additive on N. linckia and C. vulgaris, respectively, at pH 7.5 and 6.8, and synergistic at pH 6. 0 and 4.5. In the presence of 60 and 100 mu M PO43- an increased NaF c oncentration (in the AlCl3 + NaF combination) was required to produce the same degree of inhibition in ATP synthesis and ATPase activity, To xicity of fluoroaluminate was reduced in the presence of EDTA and citr ate, Except for beryllium to some extent, combinations of cadmium, cob alt, iron, manganese, tin and zinc with fluoride were not as effective as aluminium in inhibiting the ATPase activity, The presence of a 100 kDa protein band in SDS-PAGE of both control as well as AlCl3 + NaF-t reated samples suggested that AlF4- inhibits the ATPase activity by ac ting as a functional barrier without affecting the structure of the en zyme.