AOYAMA, H.

DOMINGOS, N.

JONSSON, C. M.

English

Repository Open Access to Scientific Information from Embrapa

V40In vitro effects of metais on the acid phosphatase from the microalgae Pseudokirchneriella subcapitataCláudio M artinJonsson1'*, Neusa Domingos1, Hiroshi Aoyama21 Embrapa Environment, Jaguariuna, SP, Brazil, 2 UNICAMP/1B, Campinas, SP, BrazilAcid phosphatase plays im portant roles in algae metabolism such availability/recycling of inorganic phosphate and autophagic digestive processes. Chemicals released into the environment from agricultural activities and through industrial and urban wastes, may impair algae phosphatase activity. The aim of this work was to evaluate the in vitro activation/inhibition effect of 10 metais, commonly present as contam inants in soil and water, on the acid phosphatase extracted from the green algae Pseudokirchneriella subcapitata. Results dem onstrated that Hg2+, Al3+, Mo2*, Pb2+, Se2+ and Cd2+ inhibited the enzyme activity in 56.3, 54.5, 30.6, 25.5, 23.1 and 11.5%, respectively. This corresponds to the maximum percentage of effect attained at the metal concentrations tested (0.02-2.0 mM). On the other hand, Cu2+, Zn2+, Ni2+ and Cr3+ exhib- ited an increm ent on phosphatase activity equal to 95.5, 87.6, 77.6 and 42.8%, respectively. Kinetics param eters values were calculated for the metais that showed highest effects. Thus, Kj (inhibition constant) and I<d (dissociation constant) values equal to 36.50 and 1.64 |xM were determ ined for Hg2+ and Cu2+, respectively. A non-competitive inhibition mechanism was attributed to the former. Results improved the understanding of the basic events of the impact of metais at biochemical leveis in prim ary producers organisms.Acknowledgements: Financial support from Embrapa, FAPESP and CNPq is gratefully acknowledged.doi:10.1016/j.toxlet.2008.06.431

In vitro effects of metals on the acid phosphatase from the microalgae Pseudokirchneriella subcapitata.

http://www.alice.cnptia.embrapa.br/bitstream/doc/31719/1/2008RA006.pdf

In vitro effects of metals on the acid phosphatase from the microalgae Pseudokirchneriella subcapitata.

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