AOYAMA, H.

DOMINGOS, N.

JONSSON, C. M.

SILVA, E. F. da

TESSARI, C. M.

English

Repository Open Access to Scientific Information from Embrapa

knhr* ■ r i n  u i ..1i í:rçariiJaçaojtp g ilrn a i...........l i t ..— -um os :üPfogràrna Jovem iS.tslú..„ailislllmmBusca de Resumosjm uFeSBE2004 - Meio Ambiente29.005EFFECT OF COPPER ON THE ACTIVITY OF ACID PHOSPHATASE OF THE MICROALGAE SELENASTRUM CAPRICORNUTUM. Jonsson.cM. ; Tessari.C. M, ; Domingos ,N. . ; Silva,M. E. F. da ”, Aoyama.H.; Toxicologia, EMBRAPA ; Bioquímica - IB, UNICAMP .Objetivo; Copper is widely used in agriculture as fungicide, This element may also be present as a contam inant in sewage sludge applied to agricultural lands. The presence o f copper in the water environment may have detrimental e ffe c ts  on aquatic organisms, including algae, where it can a ffe c t enzym atic system s. Algae acid phosphatase plays important roles in the metabolism such as decomposing organic phosphate into free phosphate; autophagic digestive process recycling cellular materials and zygote  formation during reproduction. This work describes the ac tiva to r in vitro e ffe c t o f copper on the acid phosphatase ac tiv ity  o f the green algae Selenastrum  capricornutum.Métodos e ResuHtados; The enzyme ac tiv ity  was determ ined using p- nitrophenyiphosphate as substrate, measuring the p-nitrophenol formation at 40S nm. The enzyme ac tiv ity  was 50% increased in the presence of 1.8 pM Cu++. The d issociation constan t Cu++-enzyme was determ ined to be 1.6 pM, Km, Vmax, activation  energy (Ea) and enzyme stab ility  were determ ined in the absence or presence o f Cu++. in  the presence o f 0.2 mM Cu++, Km and Ea decreased, whereas Vmax did not significantly changed.Conclusões; Our results suggest that the ac tiva to r e ffe ct o f copper might be due to the decrease in the Km and Ea values and to an increase o f the enzyme thermal stability.Apoio Financeiro; FAPESP.CNPq,EMBRAPA iv '

Effect of copper on the activity of acid phosphatase of the microalgae selenastrum capricornutum.

http://www.alice.cnptia.embrapa.br/bitstream/doc/1021562/1/2005RA095.pdf

Effect of copper on the activity of acid phosphatase of the microalgae selenastrum capricornutum.

Abstract

Similar works

Full text

Available Versions

Repository Open Access to Scientific Information from Embrapa