The effect of sulphates on partitioning of pectinases in aqueous two-phase systems

Abstract

The effect of various sulphate salts on the partitioning of endo-pectinase and exo-pectinase in aqueous two-phase systems, composed of polyethylene glycol and dextran, was studied. Presence of ammonium sulphate and sodium sulphate at concentration 15 mmol/l in the system polyethylene glycol 4000/crude dextran, at tie-line length 7.44%, increased partition coefficient of endo-pectinase 1.25 and 1.2 fold, respectively. Ammonium sulphate at 15 mmol/l and sodium sulphate at 5 mmol/l enhanced partition coefficient for exo-pectinase for about 60% in comparison to the system without salts. Addition of magnesium and sodium sulphate to a final concentration of 0.3 mmol/l in the system containing polyethylene glycol 6000/dextran 500 000, at tie-line length 6.26%, increased the partition coefficient of endo activity for 95% and 32%, respectively. Both salts at the same concentration increased partition coefficient of exo activity 1.5 and 3 times, respectively, in comparison to the system without salts.U radu je ispitan uticaj razlicitih sulfata na raspodelu aktivnosti endo-pektinaze i egzo-pektinaze u vodenim dvofaznim sistemima, sastavljenim od po-lietilen glikola i dekstrana. Dodatak amonijumsulfata i natrijumsulfata u dvofazni sistem polietilen glikol 4000/sirovi dekstran na veznoj liniji 7,44%, u koncentraciji od 15 mmol/l povecao je koeficijent raspodele endo-pektinaze 1,25, odnosno 1,2 puta, dok su vrednosti K za egzo aktivnost u prisustvu 15 mmol/l amonijum sulfata i 5 mmol/l natrijumsulfata bile za oko 60% vece u odnosu na sistem bez soli. Prisustvo magnezijumsulfata i natrijumsulfata u sistemu polietilen glikol 6000/dekstran 500000 na veznoj liniji duzine 6,26%, u koncentraciji od 0.3 mmol/l povecalo je K endo aktivnosti za 95%, odnosno 32%. Pri istoj koncentraciji obe soli koeficijent raspodele egzo-pektinaze povecan je 1,5, odnosno 3 puta, u odnosu na sistem bez soli.