Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.1.17 (ornithine decarboxylase)
 6,351 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to develop a method for the immunocytochemical detection of ornithine decarboxylase (ODC), EC 4.1.1.17, we have prepared and characterized monoclonal antibodies (MAbs) against ODC. The primary structure of rat ODC (Rattus Norvegicus) was used for the selection of an epitope by computer calculations. The epitope (P16), a hexadecapeptide representing ODC-(345-360), was synthesized by means of solid phase peptide synthesis and coupled to a carrier protein. A bovine serum albumin conjugate of the P16 peptide was used as the immunogen for the production of MAbs in mice. Hybridoma clones were screened and the specificity of the monoclonal antibodies was tested in an ELISA utilizing a thyroglobulin conjugate of the hexadecapeptide. Two hybridoma cell lines were developed, i.e., MP16-2 and MP16-3. The epitope specificity of the MAbs produced by these cell lines was characterized in an ELISA using a set of small peptides representing parts of the P16 hexadecapeptide chain. MP16-2 recognized the ODC-(355-360) portion whereas MP16-3 reacted with the ODC-(345-350) part of the hexadecapeptide. Further studies showed that both MAbs also recognized native ODC but not the inhibited (i.e., ODC labelled with 3H-DFMO) enzyme indicating that the selected epitope was associated with the active site of ODC or a locus in its direct vicinity.
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PMID:Preparation and characterization of monoclonal antibodies against ornithine decarboxylase. 768 41

Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors (AMPARs) mediate the majority of fast excitation in the CNS. Receptors lacking GluR2 exhibit inward rectification and paired-pulse facilitation (PPF) due to polyamine (PA)-dependent block and unblock, respectively. In this study, we tested whether rectification and PPF in immature, but not mature, pyramidal neurons depend not only on the absence of functional GluR2 but also on the level of endogenous PAs. Whole cell recordings were obtained from layer V pyramidal neurons of P12-P14 or P16-P20 rats in the presence or absence of spermine in the pipette (50 microM). Isolated minimal excitatory synaptic responses were obtained, and paired (20 Hz) stimuli were used to investigate the rectification index (RI) and paired-pulse ratio (PPR). Spermine and its synthetic enzyme, ornithine decarboxylase (ODC), expression was examined using immunostaining and Western blot, respectively. At the immature stage (<P15) inclusion of intracellular spermine increased rectification and PPF for evoked excitatory postsynaptic currents (EPSCs) but had little or no effect on either measure in more mature (P16-P20) pyramidal neurons. Depletion of PAs reduced rectification suggesting that endogenous PAs play a critical role in functional regulation of AMPARs. Spermine immunoreactivity and ODC expression in immature rat neocortex (<P15) were greater than more mature tissue by approximately 20 and 60%, respectively. These results provide further support for the idea that excitatory synapses on immature neocortical pyramidal neurons ubiquitously contain AMPA receptors lacking the GluR2 subunit and that the level of endogenous PAs plays an important role in modulating AMPAR-dependent neurotransmission.
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PMID:Polyamines modulate AMPA receptor-dependent synaptic responses in immature layer v pyramidal neurons. 1584 96