Linked Life Data

6272

Source:http://linkedlifedata.com/resource/pubmed/id/6272

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1976-9-1
pubmed:abstractText
1. The transient kinetics of reduction of the 470-nm absorption band in benzylamine oxidase by substrate at different pH values between 6 and 10 have been studied by stopped-flow techniques, and substituent effects on kinetic parameters for the reduction process have been examined using a series of ring-substituted benzylamine derivatives as the substrates. 2. Reduction of the enzyme by substrate takes place in two kinetically distinguishable steps, with the intermediate formation of an enzyme-substrate complex in which the substrate appears to be covalently bound through its amino group to the prosthetic group of the enzyme, possibly in the form of an amine-pyridoxal Schiff-base. 3. The apparent stability of the enzyme-substrate complex shows no obvious dependence on the electronic properties of the amine substrates, but is strongly pH-dependent in a way suggesting that substrate-binding involves the non-protonated amines, exclusively, and requires the presence of the acid form of an ionizing group in the enzyme with apparent pKa of 8.8. 4. Reduction of the enzymatic 470-nm chromophore and release of the aldehyde product of the catalytic process are rate-limited by the same monomolecular reaction step involving the enzyme-substrate complex. Rate constants for the rate-limiting reaction exhibit no significant dependence on pH between 6 and 10, but correlate with Hammett sigma-values for the ring-substituted benzylamine derivatives tested, yielding a phi-value of + 0.3.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
321-6
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Effect of pH on the transient reduction of pig-plasma benzylamine oxidase by benzylamine derivatives.
pubmed:publicationType
Journal Article