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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-6-8
pubmed:abstractText
o-Phthaldialdehyde caused irreversible inhibition of rabbit muscle pyruvate kinase following preliminary formation of an enzyme-reagent complex. At pH 7.5, 35 degrees C, the dissociation constant for the complex and the maximal pseudo-first-order rate constant for covalent modification were 0.32 +/- 0.08 mM and 2.54 +/- 0.23 min-1, respectively. The inactivation was accompanied by uv-spectral changes pointing to isoindole formation, with a limiting stoichiometry of 1 isoindole linkage per enzyme subunit. Phosphoenolpyruvate, ADP, and ATP effectively protected the enzyme against inactivation, suggesting that the active site is the target of o-phthaldialdehyde action. As native and modified enzymes were indistinguishable with respect to mobility of the major band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it was concluded that the crosslinkage was intrasubunit in character, and that the amino acid residues involved must be closely positioned in the polypeptide backbone. Lysine 366, previously shown to be selectively reactive toward 2',3'-dialdehyde ADP (Bezares et al., 1987, Arch, Biochem. Biophys. 253, 133-137), and cysteine 325 or 357 are implicated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
32-6
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Subunit level crosslinking of rabbit muscle pyruvate kinase by o-phthaldialdehyde.
pubmed:affiliation
Department of Biochemistry, School of Pharmacy, Hacettepe University, Ankara, Turkey.
pubmed:publicationType
Journal Article