title: Purification and characterization of a novel type of protocatechuate 3,4-dioxygenase with the ability to oxidize 4-sulfocatechol.
abstract: 4-Aminobenzenesulfonate is degraded via 4-sulfocatechol by a mixed bacterial culture that consists of Hydrogenophaga palleronii strain S1 and Agrobacterium radiobacter strain S2. From the 4-sulfocatechol-degrading organism A. radiobacter strain S2, a dioxygenase that converted 4-sulfocatechol to 3-sulfomuconate was purified to homogeneity. The purified enzyme also converted protocatechuate with a similar catalytic activity to 3-carboxy-cis, cis-muconate. Furthermore, the purified enzyme oxidized 3, 4-dihydroxyphenylacetate, 3,4-dihydroxycinnamate, catechol, and 3- and 4-methylcatechol. The enzyme had a mol. wt. of about 97,400 as determined by gel filtration and consisted of two different types of subunits with mol. wt. of about 23,000 and 28,500. The NH2-terminal amino acid sequences of the two subunits were determined. An isofunctional dioxygenase was partially purified from H. palleronii strain S1. A. radiobacter strain S2 also induced, after growth with 4-sulfocatechol, an rising dbl quote, "ordinary" protocatechuate 3,4-dioxygenase that did not oxidize 4-sulfocatechol. This enzyme was also purified to homogeneity, and its catalytic and structural characteristics were compared to the "4-sulfocatechol-dioxygenase" from the same strain.
authors.affiliation: Institut für Mikrobiologie, Universität Stuttgart, Allmandring 31, D-70569 Stuttgart, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Hammer
authors.forename: A
authors.initials: A
authors.lastname: Stolz
authors.forename: H
authors.initials: H
authors.lastname: Knackmuss
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology* / Q000378:metabolism; D001673:Biodegradation, Environmental; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D011520:Protocatechuate-3,4-Dioxygenase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D012231:Rhizobium / Q000201:enzymology / Q000378:metabolism; D013379:Substrate Specificity; D013425:Sulfanilic Acids / Q000378:metabolism*
chemical_list: D013425:Sulfanilic Acids; D011520:Protocatechuate-3,4-Dioxygenase