Publications

• Oxygenation and spontaneous deamination of 2-aminobenzenesulphonic acid in Alcaligenes sp. strain O-1 with subsequent meta ring cleavage and spontaneous desulphonation to 2-hydroxymuconic acid.

  Junker F., Field J.A., Bangerter F., Ramsteiner K., Kohler H.P., Joannou C.L., Mason J.R., Leisinger T., Cook A.M.

  2-Aminobenzenesulphonic acid (2AS) is degraded by Alcaligenes sp. strain O-1 via a previously detected but unidentified intermediate. A mutant of strain O-1 was found to excrete this intermediate, which was isolated and identified by m.s., 1H- and 13C-n.m.r. as 3-sulphocatechol (3SC). Proteins fro ... >> More

  2-Aminobenzenesulphonic acid (2AS) is degraded by Alcaligenes sp. strain O-1 via a previously detected but unidentified intermediate. A mutant of strain O-1 was found to excrete this intermediate, which was isolated and identified by m.s., 1H- and 13C-n.m.r. as 3-sulphocatechol (3SC). Proteins from cell extracts of strain O-1 were separated by anion-exchange chromatography. A multicomponent oxygenase was observed to convert 1 mol each of NADH, O2 and 2AS into 1 mol each of 3SC, NH3 and NAD+. The enzyme presumably catalysed formation of the ring of a 2-amino-2,3-diol moiety, and elimination in the amino group led to a rearomatization. 3SC was further degraded via meta ring cleavage, which could be prevented by inactivation of the 3-sulphocatechol-2,3-dioxygenase (3SC23O) with 3-chlorocatechol. In Tris buffer, the separated 3SC23O catalysed the reaction of 1 mol each of 3SC and O2 involving a transient yellow intermediate, and release of 1 mol of sulphite and two organic products. The major product was identified by n.m.r. and by g.c./m.s. as 5-carboxypenta-2,4-dien-5-olide (CPDO), an indicator of formation of 2-hydroxymuconic acid (2HM). The second product was identified as the Z,E isomer of 2HM by comparison with authentic material. When the CPDO in the product mixture was chemically hydrolysed to (Z,E)-2HM, 1 mol of (Z,E)-2HM/mol of 3SC was observed. If oxygenation of 3SC by 3SC23O was carried out in phosphate buffer, only a single product was detected, a keto form of 2HM. This dioate was also formed from authentic (Z,E)-2HM in phosphate buffer. Formation of the natural product (Z,E)-2HM from the xenobiotic, 3SC, seems to involve oxygenation to the unstable 2-hydroxy-6-sulphonomuconic acid semialdehyde, which hydrolyses spontaneously to 2HM. There would appear to be at least one spontaneous reaction per enzyme reaction in this pathway. << Less

  Biochem J 300:429-436(1994) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• 3-Sulphocatechol 2,3-dioxygenase and other dioxygenases (EC 1.13.11.2 and EC 1.14.12.-) in the degradative pathways of 2-aminobenzenesulphonic, benzenesulphonic and 4-toluenesulphonic acids in Alcaligenes sp. strain O-1.

  Junker F., Leisinger T., Cook A.M.

  Alcaligenes sp. strain O-1 utilizes three sulphonated aromatic compounds as sole sources of carbon and energy for growth in minimal salts medium-benzenesulphonate (BS), 4-toluenesulphonate (TS) and 2-aminobenzenesulphonate (2AS). The degradative pathway(s) in 2AS-grown cells are initiated with mem ... >> More

  Alcaligenes sp. strain O-1 utilizes three sulphonated aromatic compounds as sole sources of carbon and energy for growth in minimal salts medium-benzenesulphonate (BS), 4-toluenesulphonate (TS) and 2-aminobenzenesulphonate (2AS). The degradative pathway(s) in 2AS-grown cells are initiated with membrane transport, NADH-dependent dioxygenation and meta ring cleavage. The specific activity of the NADH-dependent dioxygenation(s) varied with the growth phase and was maximal near the end of exponential growth for each growth substrate. Cells were harvested at this point from BS-, TS- and 2AS-salts medium. Cells grown with each sulphonated substrate could oxygenate all three compounds, but only 2AS-grown cells consumed 2 mol O2 per mol 2AS or BS or TS. BS- and TS-grown cells consumed 2 mol O2 per mol BS or TS but failed to oxygenate the product of oxygenation of 2AS, 3-sulphocatechol (3SC). These observations were repeated with cell extracts and we concluded that there were two sets of desulphonative pathways in the organism, one for 2AS and one for BS and TS. We confirmed this hypothesis by separating the degradative enzymes from 2AS-, BS- or TS-grown cells. A 2AS dioxygenase system and a 3SC-2,3-dioxygenase (3SC23O) were detected in 2AS-grown cells only. In both BS- and TS-grown cells a dioxygenase system for BS and TS was observed as well as a principal catechol 2,3-dioxygenase (C23O-III), neither of which was present in 2AS-grown cells. The 3SC23O was purified to near homogeneity, found to be monomeric (M(r) 42,000), and to catalyse 2,3-dioxygenation to a product that decayed spontaneously to sulphite and 2-hydroxymuconate. The 2AS dioxygenase system could cause not only deamination of 2AS but also desulphonation of BS and TS. The BS dioxygenase could desulphonate BS and apparently either desulphonate or deaminate 2AS. Strain O-1 thus seems to contain two putative, independently regulated operons involving oxygenation and spontaneous desulphonation(s). One operon encodes at least the 2AS dioxygenase system and 3SC23O whereas the other encodes at least the BS/TS dioxygenase system and C23O-III. << Less

  Microbiology 140:1713-1722(1994) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.