Linked Life Data

1807157

Source:http://linkedlifedata.com/resource/pubmed/id/1807157

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-5-8
pubmed:abstractText
Pyridoxamine 5'-phosphate in 18 microliters of human capillary blood plasma is determined by catalytic amplification using the apoenzyme of aspartate aminotransferase. Prior isolation from interfering substances is accomplished by employment of a cation exchange resin in batch operation. The procedure consists of the following stages. Stage I, denaturation of proteins. Trichloroacetic acid is used to precipitate plasma proteins and liberate any bound coenzyme. Dilute NaCl is added to expand the volume thus minimizing coenzyme entrapment in the precipitate. Stage II, isolation of the coenzyme. A sulfonated polystyrene ion exchange resin is used inside a centrifugal filter. Pyridoxamine 5'-phosphate in the supernatant from Stage I adsorbs to the resin. Pyridoxal 5'-phosphate, other organic phosphates, and Pi are removed by centrifugation. Rinsing with dilute NaBH4 destroys traces of pyridoxal 5'-phosphate and washes off residual inhibitors. Pyridoxamine 5'-phosphate is then desorbed with NaOH and Tris buffer and recovered by centrifugation. Stage III, reconstitution and assay. The desorbate from Stage II is incubated with excess apoenzyme. Specific activity of the reconstituted enzyme is measured. Interpolation from a standard curve relating enzyme specific activity and pyridoxamine 5'-phosphate concentration yields the plasma level of the cofactor. Approximately 3 h are required to carry out the procedure. Much of the coenzyme was found not be assayable if plasma was refrigerated overnight or if whole blood was left standing at room temperature for a few hours. The degradation was arrested with freezing at -80 degrees C. In a 13-day experiment involving a healthy subject, sharp rises of plasma pyridoxamine 5'-phosphate were found to occur in response to small doses of oral vitamin B6.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0003-2697
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
199
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18-24
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Determination of pyridoxamine 5'-phosphate in human blood plasma.
pubmed:affiliation
Division of Molecular Biology & Biochemistry, School of Basic Life Sciences, University of Missouri-Kansas City 64110-2499.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't