Linked Life Data

12001170

Source:http://linkedlifedata.com/resource/pubmed/id/12001170

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2002-5-23
pubmed:abstractText
We developed a kinetic model that describes a heterogeneous reaction system for the production of D-p-hydroxyphenylglycine from D,L-p-hydroxyphenyl-hydantoin using D-hydantoinase of Bacillus stearothermophilus SD1 and N-carbamoylase of Agrobacterium tumefaciens NRRL B11291. As a biocatalyst, whole cells with separately or co-expressed enzymes were used. The reaction system involves dissolution of substrate particles, enzymatic conversion, racemization of the L-form substrate, and transfer of the dissolved substrate, intermediate, and product through the cell membrane. Because the two enzymes have different pH optimum, kinetic parameters were evaluated at different pH for the reaction systems. The model was simulated using the kinetic parameters and compared with experimental data, and it was found that the kinetic model well describes the behavior of the reaction systems using whole cells with separately and co-expressed enzymes. Factors affecting the kinetics of the reaction systems were analyzed on the basis of the kinetic model. In the reaction system with separately expressed enzymes, racemization rate and transport of the reaction intermediate (N-carbamoyl-D-p-hydroxyphenylglycine) were revealed to be the limiting factors at neutral pH, resulting in accumulation of intermediate in the reaction medium. At alkaline condition, on the other hand, inhibition of N-carbamoylase by ammonia was severe, and thereby the reaction rate significantly reduced. In the co-expressed enzyme system, accumulation of intermediate was negligible in the reaction medium, and the improved performance was observed compared to that with separately expressed enzymes. The present model might be applied for the optimization and development of the reaction system using two sequential enzymes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3592
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Wiley Periodicals, Inc.
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
78
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
779-93
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Modeling and kinetic analysis of the reaction system using whole cells with separately and co-expressed D-hydantoinase and N-carbamoylase.
pubmed:affiliation
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1, Kusung-dong Yusung-gu, Taejon, 305-701, Korea.
pubmed:publicationType
Journal Article, Comparative Study, Validation Studies