Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.99.1 (NADPH-diaphorase)
 3,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the central nervous system nitric oxide appears to be critically involved in a number of physiological and pathological processes. Although there is convincing evidence for expression of nitric oxide synthase in cultured glial cells, demonstration of this enzyme in glial cells in situ remained largely unsatisfactory. In the present study we applied immunostaining to freeze-dried sections of snap-frozen hippocampi and cerebella of rats and to sections of freeze-dried brain tissue in order to minimize diffusion artefacts and thus to obtain more precise information about the true in situ localization of nitric oxide synthase. Here we show that astrocytes and Bergmann glia react strongly with antibodies raised against cerebellar nitric oxide synthase and against a type I nitric oxide synthase-specific C-terminal peptide, respectively. This finding was further substantiated by histochemical localization of NADPH-diaphorase activity in astrocytes and Bergmann glia as well as by immunoreactivity of both types of glia cells with antibodies to the NADPH-delivering enzyme glucose-6-phosphate dehydrogenase. We conclude, that astrocytes are important sites of nitric oxide synthase I in brain, suggesting that these cells might use nitric oxide as gaseous messenger molecule for various aspects of glia-neuron signalling.
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PMID:Astrocytes and Bergmann glia as an important site of nitric oxide synthase I. 892 3

Formation of enzymatically active [NiFe] hydrogenases is dependent on a number of posttranslational steps, including metal attachment to a precursor of the catalytic subunit, truncation of a small C-terminal peptide from the precursor, and oligomerisation of the subunits. Two amino acid replacements were introduced by site-directed mutagenesis at the C-terminal proteolytic cleavage site of HoxH, the Ni-containing subunit of the cytoplasmic NAD-reducing hydrogenase of Alcaligenes eutrophus H16. Replacement of Ala465, the first residue of the 24-amino-acid cleaved polypeptide, by Pro yielded a form of HoxH that was blocked in C-terminal proteolysis. This HoxH subunit, although capable of binding Ni, was blocked in formation of a stable tetrameric holoenzyme. In the second mutant, the C-terminal extension of HoxH was eliminated by substituting the Ala codon for a translational stop codon. Although this mutant subunit was able to form the oligomeric holoenzyme, it was devoid of Ni. Both mutant proteins contained only traces of H2-activating functions. H2-dependent reduction of NAD and benzylviologen, and D2/H+-exchange activity were almost completely abolished, while the NADH oxidoreductase activity, mediated by the diaphorase moiety of the hydrogenase, was retained. These results allow the following conclusions: the C-terminal extension of HoxH is neccessary to direct specific Ni insertion into the hydrogenase; subunit assembly to the holoenzyme is not dependent on Ni insertion; and a precursor with the C-terminal peptide is not competent for assembly.
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PMID:C-terminal extension of the H2-activating subunit, HoxH, directs maturation of the NAD-reducing hydrogenase in Alcaligenes eutrophus. 915 77

We have made an immunohistochemical study of the vomeronasal (VN) complex of 12-day-old rats to characterize the innervation of its blood vessels. The VN complex can be subdivided into rostral, middle and caudal segments, each one with a particular vascularization pattern. Several small vessels were associated with the rostral segment, whereas a large venous sinus ran along the middle and caudal segments. Immunostaining for alpha-smooth muscle actin demonstrated that the muscular sheath was asymmetric, with more cells layers in its lateral than in its medial walls. Nerves were demonstrated with antisera against protein gene product 9.5 (PGP), and against several molecules associated with specific classes of nerve fibers: the C-terminal peptide of neuropeptide Y (CPON), calcitonin gene-related peptide (CGRP), substance P (SP), galanin (GAL), vasoactive intestinal peptide (VIP) and neuronal nitric oxide synthase (NOS). The latter, was also studied with NADPH-diaphorase. Vascular associated fibers exhibited NOS-, CPON-, GAL-, CGRP-, SP- and VIP-immunoreactivity. Only the vessels of the rostral segment showed VIP-immunoreactive fibers. Each wall of the venous sinus exhibited different types of nerve fibers. CPON-, GAL-, CGRP- and SP-immunoreactive fibers concentrated in the medial wall, whereas NOS-immunoreactive ones concentrated in the lateral wall. This distribution of vascular fibers, plus the presence of sensory fibers exhibiting CGRP-, SP- and GAL-immunoreactivity within the pseudostratified epithelium of the VN tube, would be relevant to understand the operation of the pumping mechanism regulating influx and efflux from the VN tube.
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PMID:Innervation of blood vessels in the vomeronasal complex of the rat. 980 88