title: Immobilized metal-ion affinity partitioning of NAD(+)-dependent dehydrogenases in poly(ethylene glycol)-dextran two-phase systems.
abstract: Affinity partitioning of yeast alcohol dehydrogenase (YADH), lactate dehydrogenase from rabbit muscle (MLDH) and lactate and malate dehydrogenases from pig heart (HLDH and HMDH, respectively) were studied in aqueous two-phase systems containing metal ions (Cu2+, Ni2+, Zn2+ and Cd2+) chelated by iminodiacetate-poly(ethylene glycol) (IDA-PEG). The partitioning behaviour of the enzymes in the presence of Cu(II)-IDA-PEG was studied as a function of the concentration of NaCl, the pH of the medium and the concentration of added selected agents. It was demonstrated that the partition effect (delta log K) of dehydrogenases in the presence of Cu(II)-IDA-PEG and the affinity of enzymes for immobilized Cu2+ ions increases in the order MLDH > YADH > HMDH > or = HLDH. It was shown that the determined variations in the enzyme affinities for Cu(II)-IDA-PEG might be related to the differences in the content of histidine residues accessible to the solvent.
authors.affiliation: Department of Research, Institute of Biotechnology Fermentas, Vilnius, Lithuania.
authors.forename: H
authors.initials: H
authors.lastname: Pesliakas
authors.forename: V
authors.initials: V
authors.lastname: Zutautas
authors.forename: B
authors.initials: B
authors.lastname: Baskeviciute
mesh_terms: D000426:Alcohol Dehydrogenase / Q000302:isolation & purification*; D000818:Animals; D002846:Chromatography, Affinity / Q000379:methods*; D003911:Dextrans / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000302:isolation & purification*; D008291:Malate Dehydrogenase / Q000302:isolation & purification*; D008670:Metals; D009243:NAD / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry*; D011817:Rabbits; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013552:Swine
chemical_list: D003911:Dextrans; D008670:Metals; D009243:NAD; D011092:Polyethylene Glycols; D000426:Alcohol Dehydrogenase; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase