Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162473 (Frey)
 2,599 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumor necrosis factor-alpha (TNF) is involved in the generation of inflammatory and neuropathic pain. The synthetic hydroxamic acid based metalloprotease inhibitor TAPI blocks cleavage of cell surface TNF and thus reduces levels of the mature 17-kDa TNF polypeptide in activated macrophages and T-cells. We have previously shown that pharmacologic inhibition of TNF production reduces pain related behaviors in mice with chronic constriction injury (CCI). Here we investigated whether blockage of TNF shedding by administration of TAPI would diminish hyperalgesia in animals with partial nerve injury. We injected 0.5 mg of the inhibitor epineurially once daily to mice with CCI for 7 days. The animals were tested for withdrawal thresholds to heat to test for thermal hyperalgesia and to von Frey hairs to assess mechanical allodynia. Mice with CCI developed thermal hyperalgesia and mechanical allodynia by day 3 after the injury. In mice treated with TAPI, a reduction of thermal hyperalgesia and mechanical allodynia of up to 50% occurred. Endoneurial TNF-immunoreactivity was reduced, but not immunoreactivity for IL-1alpha or IL-1beta. The numbers of degenerating axons and endoneurial macrophages were not affected by the treatment as compared to controls. We conclude that the metalloprotease inhibitor TAPI specifically reduces endoneurial TNF-levels after nerve injury and thereby may diminish neuropathic pain in the CCI-model.
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PMID:A metalloprotease-inhibitor reduces pain associated behavior in mice with experimental neuropathy. 940 76

The rubella virus (RUB) nonstructural (NS) protein (NSP) ORF encodes a protease that cleaves the NSP precursor (240 kDa) at a single site to produce two products. A cleavage site mutation was introduced into a RUB infectious cDNA clone and found to be lethal, demonstrating that cleavage of the NSP precursor is necessary for RUB replication. Based on computer alignments, the RUB NS protease was predicted to be a papain-like cysteine protease (PCP) with the residues Cys1152 and His1273 as the catalytic dyad; however, the RUB NS protease was recently found to require divalent cations such as Zn, Co, and Cd for activity (X. Liu, S. L. Ropp, R. J. Jackson, and T. K. Frey, J. Virol. 72:4463-4466, 1998). To analyze the function of metal cation binding in protease activity, Zn binding studies were performed using the minimal NS protease domain within the NSP ORF. When expressed as a maltose binding protein (MBP) fusion protein by bacteria, the NS protease exhibited activity both in the bacteria and in vitro following purification when denatured and refolded in the presence of Zn. Atomic absorption analysis detected 1.6 mol of Zn bound per mol of protein refolded in this manner. Expression of individual domains within the protease as MBP fusions and analysis by a Zn(65) binding assay revealed two Zn binding domains: one located at a predicted metal binding motif beginning at Cys1175 and the other one close to the cleavage site. Mutagenesis studies showed that Cys1175 and Cys1178 in the first domain and Cys1227 and His1273, the His in the predicted catalytic site, in the second domain are essential for zinc binding. All of these residues are also necessary for the protease activity, as were several other Cys residues not involved in Zn binding. Far-UV circular dichroism (CD) analysis of the MBP-NS protease fusion protein showed that the protease domain contained a large amount of alpha-helical structure, which is consistent with the results of secondary-structural prediction. Both far-UV-CD and fluorescence studies suggested that Zn did not exert a major effect on the overall structure of the fusion protein. Finally, protease inhibitor assays found that the protease activity can be blocked by both metal ion chelators and the metalloprotease inhibitor captopril. In conjunction with the finding that the previously predicted catalytic site, His1273, is essential for zinc binding, this suggests that the RUB NS protease is actually a novel virus metalloprotease rather than a PCP.
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PMID:Characterization of the zinc binding activity of the rubella virus nonstructural protease. 1084 76