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)

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.
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PMID:Mechanism of irreversible inactivation of phenylalanine-4- and tryptophan-5-hydroxylases by [4-36Cl, 2-14C]p-chlorophenylalanine: a revision. 646 31

The contribution of the dopamine-synthetic capacity of nigral neuronal subregions to their vulnerability to degeneration in idiopathic Parkinson's disease (IPD) was explored using semiquantitative in situ hybridization to study expression of mRNA encoding the rate-limiting dopamine synthetic enzyme, tyrosine hydroxylase (TH). Expression of mRNA, the structural protein, beta-tubulin, and the glycolytic enzyme, fructose-1,6, biphosphate aldolase (aldolase C) was studied in parallel in individual neurons of the substantia nigra pars compacta (SNc) in matched groups of IPD and control subjects. TH mRNA expression was found to be heterogeneously expressed in nigral neurons in control and IPD subjects. There was no significant difference in mean values for TH mRNA expression between control and IPD cases and none between nigral subregions, either in control subjects or in established IPD subjects in this study, but there was evidence for a selective upregulation of TH mRNA expression in non-melanized neurons in IPD. There was no relationship between TH mRNA expression disease duration or L-dopa dosage in the IPD group. Mean TH mRNA values for two additional 40-year-old control subjects fell within the range of values of the aged-control group. Aldolase C and beta-tubulin expression did not differ between control and IPD groups or between nigral subregions. These findings suggest that regulation of dopamine synthesis at the level of the cell body does not play a part in determining the pattern of nigral cell vulnerability in IPD. The heterogeneous pattern of TH synthesis was not age-dependent and may be of physiological significance in nigral function. There was no evidence for compensatory upregulation of TH synthesis in surviving melanized neurons in IPD but non-melanized neurons may be involved in this process. Surviving nigral neurons in IPD appear to retain the capacity for normal aldolase C and beta-tubulin peptide synthesis. Long-term L-dopa treatment does not appear to compromise normal function of nigral dopaminergic neurons.
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PMID:The vulnerability of nigral neurons to Parkinson's disease is unrelated to their intrinsic capacity for dopamine synthesis: an in situ hybridization study. 1009 11