Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-11-2
pubmed:abstractText
2,3-Dihydroxybiphenyl 1,2-dioxygenase (EC 1.13.11.39) from Pseudomonas sp. strain KKS102 (BphC) catalyzes the proximal extradiol cleavage of the catechol ring of 2,3-dihydroxybiphenyl (DHB), a key step in the biodegradation of polychlorinated biphenyl. Because the active site Fe(II) ion of the extradiol dioxygenase is colorless, it has been difficult to monitor the reaction cycle kinetics. Here, we have found that BphC binds strongly the chromophoric substrate 3-formylcatechol (3FC) as a monoanion (Kd=0.8 microM) and cleaves it two orders of magnitude slower compared to DHB under air-saturation conditions. By utilizing 3FC as a probe, the reaction cycle kinetics of BphC was monitored for the first time. The binding of 3FC occurred in a three-step process involving rapid deprotonation of 3FC. The bound monoanionic 3FC reacted slowly with O2 in three steps, occurring in sequence, the ring opening step being the slowest one.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
338
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
223-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Single-turnover kinetics of 2,3-dihydroxybiphenyl 1,2-dioxygenase reacting with 3-formylcatechol.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Seta, Ohtsu, Shiga 520-2192, Japan. teishida@belle.shiga-med.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't