RT Journal Article SR Electronic(1) A1 Bayly, Ronald C. A1 Diberardino, Dario A1 Hughes, E. John L. A1 Skurray, Ronald A.YR 1987 T1 The Purification and Properties of Two Isofunctional 2-Hydroxy-6-oxohepta-2,4-dienoate Hydrolases from Alcaligenes eutrophus Strain 345 JF Microbiology, VO 133 IS 3 SP 815 OP 822 DO https://doi.org/10.1099/00221287-133-3-815 PB Microbiology Society, SN 1465-2080, AB Two 2-hydroxy-6-oxohepta-2,4-dienoate (HOD) hydrolases have been purified to homogeneity from Alcaligenes eutrophus ATCC 17707. One, HODHII, is encoded by the TOL-like plasmid, pRA1000, and the other, HODHI, is chromosomally-encoded. HODHI and HODHII have an M r of 104 × 103 and 116 × 103, respectively, and both are dissociated by SDS into three subunits of equal size which are not linked by disulphide bonds. Both hydrolases are active against a similar range of substrates formed by the action of catechol 2,3-oxygenases, generally being more active against substrates formed from 3-alkyl- rather than 4-alkyl-substituted catechols. HODHI and HODHII had similar K m values for HOD, but HODHI had a significantly lower K m value for, and a higher activity against, 2-hydoxymuconic semialdehyde than HODHII. It was shown by immunodiffusion studies that the two hydrolases were immunologically distinct and that HODHI had no common antigenic determinants with HOD hydrolases from the Pseudomonas putida strains NCIB 9865, NCIB 10015 and mt-2; HODHII gave a line of identity with antiserum to the hydrolase from P. putida NCIB 9865. A comparison of the physico-chemical properties of HODHI and HODHII with the same properties of the HOD hydrolases from the three P. putida strains demonstrated several similarities between the five HOD hydrolases which have been purified., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-133-3-815