Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Injury induced in Escherichia coli cells by chlorination was studied from a physiological standpoint. Predictable and reproducible injury was found to occur rapidly in 0.5 mg of chlorine per liter and was reversible under nonselective conditions. There was an extended lag period in the growth of chlorinated cells not seen in control suspensions followed by the resumption of logarithmic growth at a rate equaling that of control cells. The aldolase activity of cells chlorinated in vivo was equivalent to that obtained for control cells. Oxygen uptake experiments showed that chlorinated cells underwent a decrease in respiration that was not immediatedly repaired in the presence of reducing agents. This effect was more pronouned in rich media containing reducing agents. Uptake of metabolities was inhibited by chlorine injury as shown with experiments using 14C-labeled glucose and algal protein hydrolysate.
 ...
PMID:Chlorine injury and the enumeration of waterborne coliform bacteria. 37 30

Exposure of Escherichia coli 2-oxo-4-hydroxyglutarate aldolase (4-hydroxy-2-oxoglutarate glyoxylate-lyase, EC 4.1.3.16) (molecular weight = 63 000) to phosphoric acid at pH 1.6 for 10 min at 4 degrees C causes 95% or greater inactivation. No significant effect on the rate or extent of inactivation is caused by varied aldolase concentrations or the presence of exogenous proteins. Chloride ion (50-100 mM) or 10 mM 2-oxo-4-hydroxyglutarate markedly decreases both the rate and extent of inactivation; good protection is also afforded by 10 mM pyruvate, glyoxylate, glyoxal, 2-oxoglutarate or 2-oxobutyrate. Whereas native aldolase has two free and three buried sulfhydryl groups, all five are exposed in the acid-inactivated enzyme and the molecular weight of this species at pH 1.6 is 126 000. Ultraviolet absorbance difference spectra, circular dichroism spectra and ultracentrifugation studies establish that the inactivation process is characterized by an alteration of secondary and tertiary structure as well as an aggregation to a dimer of the native molecule. Reactivation of enzyme activity to 60-80% of the original level is seen within 20 min at pH 6 to 8; examination of inactivation/reactivation as a function of pH indicates that these two processes occur via kinetically distinct pathways. Native and reactivated enzymes are identical in molecular weight, sulfhydryl titer, Km and alpha-helix content.
 ...
PMID:Dimerization occurs during the reversible acid inactivation of 2-oxo-4-hydroxyglutarate aldolase from Escherichia coli. 635 82

Intraperitoneal injection of [4-36Cl, 2-14C]p-chlorophenylalanine (pCPA) (300 mg/kg) in rats revealed absence of chlorine in pure hepatic phenylalanine hydroxyase, while the carbon label appeared a 1--4 moles/mole of [14C]tyrosine in the inactivated phenylalanine and cerebral tryptophan-5-hydroxylase. Crystalline muscle aldolase and tyrosine hydroxylase also revealed the presence of [2-14C]tyrosine from [2-14C]pCPA without inactivating these enzymes. Injection of L-[(U)-14C] tyrosine led to its incorporation into the above enzymes, but to a different degree without altering the enzyme activity. Repeated injections of p-chlorophenylacetic acid had no effect on phenylalanine or tryptophan-hydroxylase, Administration of pCPA did not change the levels of cerebral biopterins. Reexamination of the effect of cycloheximide on reversing enzymic inactivation by pCPA failed to confirm our earlier observation.
 ...
PMID:Mechanism of irreversible inactivation of phenylalanine-4- and tryptophan-5-hydroxylases by [4-36Cl, 2-14C]p-chlorophenylalanine: a revision. 646 31