Show simple item record

dc.contributorWichita State University. Department of Chemistryen_US
dc.contributor.authorWimalasena, Kandategeen_US
dc.contributor.authorWimalasena, D. Shyamalien_US
dc.identifier.citationAnalytical biochemistry. 1991 Sep 2; 197(2): 353-61.en_US
dc.descriptionFull text of this article is not available in SOAR.en_US
dc.description.abstractBased on the novel chromophoric electron donors, N,N-dimethyl-1,4-phenylenediamine (DMPD) and 2-amino-2-deoxy-L-ascorbic acid (2-aminoascorbic acid), two sensitive, convenient, and continuous spectrophotometric assays for dopamine beta-monooxygenase (EC are described. Both, DMPD and 2-aminoascorbic acid are kinetically and stoichiometrically well-behaved electron donors for dopamine beta-monooxygenase with kinetic parameters comparable to the most efficient physiological electron donor, ascorbic acid. During dopamine beta-monooxygenase turnover, DMPD is converted to its chromophoric cation radical which is stable under the standard assay conditions. The rate of the enzyme-dependent formation of DMPD cation radical under standard assay conditions could easily be followed at 515 nm with high accuracy and reproducibility. Similarly, dopamine beta-monooxygenase-mediated oxidation of 2-aminoascorbic acid results in the formation of the known, stable chromophoric product, 2,2'-nitrilodi-2(2')-deoxy-L-ascorbic acid (red pigment), which has a very strong absorption maximum at 385 nm. Both the above assays are superior to the existing assays in their convenience, reproducibility, and sensitivity for routine kinetic analysis of dopamine beta-monooxygenase and may be adopted as a simple color test for the enzyme. We propose that the above assays could also be adopted to design continuous and sensitive spectrophotometric assays for ascorbate oxidase, peptidyl alpha-amidating monooxygenase, and the chromaffin granule electron transport protein, cytochrome b561, due to their remarkable similarity to dopamine beta-monooxygenase in the chemistry of catalysis with regard to the electron donor.en_US
dc.relation.ispartofseriesAnalytical biochemistryen_US
dc.relation.ispartofseriesAnal. Biochem.en_US
dc.subjectResearch Support, Non-U.S. Gov'ten_US
dc.subject.lcshAscorbic Acid/chemistryen_US
dc.subject.meshAscorbic Acid/analogs & derivativesen_US
dc.subject.meshChemistry, Clinicalen_US
dc.subject.meshChromaffin Granules/enzymologyen_US
dc.subject.meshDopamine beta-Hydroxylase/analysisen_US
dc.titleContinuous spectrophotometric assays for dopamine beta-monooxygenase based on two novel electron donors: N,N-dimethyl-1,4-phenylenediamine and 2-aminoascorbic aciden_US
dc.coverage.spacialUnited Statesen_US
dc.description.versionpeer revieweden_US
dc.rights.holderCopyright © 1991, Elsevieren_US

Files in this item


There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record