Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Columns containing ribosomes translating poly(U) covalently bound with cellulose (solid-phase translating system) were used to study translocation in ribosomes. It is shown that the passing of elongation factor G (EF-G) with the non-cleavable analog of GTP (GMP-PCP) through a column containing pre-translocated ribosomes results in the increase of competence for puromycin (i. e. to the transition of pre-translocated peptidyl-tRNA into the post-translocated state) just as in the case of the passing of EF-G with GTP. On the other hand, it is shown that the passing of EF-G with GMP-PCP through a column with pre-translocated ribosomes makes them capable of binding the next aminoacyl-tRNA (i. e. leads to the vacation of the ribosomal A-site). Thus, by means of the two independent tests it is shown that EF-G-promoted translocation in the ribosome can proceed without GTP hydrolysis. On the basis of the data obtained, a controlled step-wise elongation of polypeptide with the participation of EF-G without GTP cleavage has been carried out in the solid-phase column system of translation.
Mol Biol (Mosk)
PMID:[Translocation in ribosomes induced by elongation factor G without cleavage of GTP. Study using a solid phase translation system in columns]. 25 70

We have shown previously that cultured human lung cancer cells of different histologic types express multiple opioid receptors that can regulate their growth. In this report, we show that these cells also express specific, saturable, and high-affinity binding sites (Kd approximately 1 nM) for the non-opioid phencyclidine (PCP), [(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,b]cyclohepten-5,10-imine hydrogen maleate] (MK-801) and sigma N-allylnormetazocine (SKF-10,047) receptor ligands. Characterization of these binding sites showed them to be protein in nature and sensitive to the guanine nucleotide GTP. Pharmacological studies showed that (+) MK-801 and (+) SKF-10,047 competed with each other for their binding sites and also for the methadone binding site present in these cells. However, the mu and delta opioid ligands did not compete for (+) MK-801 and (+) SKF-10,047 binding sites. In addition, these binding sites on lung cancer cells appear to be distinct from the N-methyl D-aspartate/PCP receptor ionophore complex reported to be present in rat brain. MK-801 and SKF-10,047, at nM concentrations, were found to inhibit the growth of these cells in culture within a few hours of exposure, and this effect was irreversible after 24 h. The growth effects of these ligands could not be reversed by the opioid antagonist naloxone, suggesting involvement of nonopioid type receptors in the actions of these ligands. The abundant expression of biologically active MK-801 and SKF-10 047 binding sites in these cell lines, distinct from those in rat brain, suggests that these cell lines may prove to be a valuable source for further characterization and purification of these binding sites.
Mol Biol Cell 1992 Jun
PMID:Biologically active MK-801 and SKF-10,047 binding sites distinct from those in rat brain are expressed on human lung cancer cells. 132 49

This paper describes the cloning of a gene (pcp) coding for pyrrolidone carboxylyl peptidase (PYRase), an enzyme which selectively removes N-terminal pyroglutamic acid residues from polypeptides. This gene was isolated from Streptococcus pyogenes by construction of a gene library with a bacteriophage lambda-derived cosmid-Escherichia coli host system. Nucleotide sequence determination of a 1.3 kb restriction fragment revealed a 645 bp open reading frame encoding a 215-amino-acid product of M(r) 23,135 consistent with the 26 kDa polypeptide obtained from in vivo overexpression in E. coli. Southern hybridization confirmed that pcp is a single-copy gene on the S. pyogenes chromosome. 5' and 3' endpoint mapping of the 0.7 kb specific transcript observed by Northern analysis permitted the identification of transcriptional initiation and termination signals. Structural features of the pcp gene product from S. pyogenes are discussed and compared with that from Bacillus subtilis. The lack of sequence identity with any other known protein or nucleotide sequence suggests that this enzyme belongs to a new class of peptidase.
Mol Microbiol 1992 Aug
PMID:Molecular characterization of pcp, the structural gene encoding the pyrrolidone carboxylyl peptidase from Streptococcus pyogenes. 135 25

We have developed a highly specific and sensitive technique for the detection of Pneumocystis carinii DNA using DNA amplification by the polymerase chain reaction (PCR). PCR products are detected by agarose gel electrophoresis and Southern hybridization to an oligonucleotide probe. Here we report the calibration of parasite numbers with amplification and hybridization signals and show that we can detect P. carinii to a lower limit of one to two organisms. The quantification of this diagnostic technique allows us to establish the number of organisms in a clinical sample which correspond to pneumocystis pneumonia or to sub-clinical pulmonary colonization.
Mol Cell Probes 1992 Apr
PMID:Quantification of the detection of Pneumocystis carinii by DNA amplification. 151 40

Phencyclidine (PCP) receptors have been solubilized from rat forebrain membranes with the zwitterionic detergent 3-(3-cholamidopropyl)dimethylammonio-1-propanesulfonate. Specific binding of the potent PCP receptor ligands [3H]thienyl-phencyclidine (TCP) and [3H]MK-801 was restored by incorporating extracted membrane protein into lipid vesicles prepared from a total brain lipid extract. A nearly quantitative recovery of solubilized receptor activity was achieved; this was dependent upon both the concentration of detergent used during membrane solubilization and the concentration of added lipid used during the reconstitution. The single, saturable, binding site measured for both [3H]TCP and [3H]MK-801 in solubilized and reconstituted preparations exhibited properties similar to those of the high affinity PCP binding site labeled by these ligands in brain membranes. The ability of ligands selective for this site (MK-801, TCP, and dexoxadrol) to competitively displace specific [3H]TCP binding was retained after solubilization and reconstitution, although IC50 values measured for these ligands were shifted to higher concentrations. Levoxadrol and haloperidol were ineffective at displacing the radioligand binding in both membrane and vesicle preparations. The additive and dose-dependent ability of glutamate and glycine to enhance [3H]TCP binding to the solubilized/reconstituted receptor further suggests that a direct interaction with the N-methyl-D-aspartate receptor/ion channel complex has been preserved in the vesicle preparations. The photoaffinity labeling of two polypeptides (Mr 98,000 and 59,000) by azido-[3H]PCP was demonstrated in the vesicle preparations; this was largely prevented by competitive displacement of the radioligand with PCP before photolysis. These results establish both an essential lipid dependency and polypeptide composition for the high affinity, haloperidol-insensitive, PCP receptor in brain.
Mol Pharmacol 1991 Nov
PMID:High efficiency reconstitution of a phencyclidine/MK-801 receptor binding site solubilized from rat forebrain membranes. 165 3

Phosphoinositide-specific phospholipase C (PI-PLC) activity in whole homogenates of mouse pancreatic islets decreased 60-85% when the homogenates were incubated at 37 degrees C for 1 h in the presence of down to micromolar concentrations of Ca2+. Ca(2+)-induced inactivation was augmented by calmodulin, the phorbol ester 12-O-tetradecanoylphorbol 13-acetate in the presence of ATP-Mg, and by Mg2+. Inactivation was inhibited when ATP was removed and completely abolished by trifluoperazine and EGTA. Inactivation was not affected by the non-phosphorylating ATP analogue, AMP-PCP, GMP-PNP, glucose, Zn2+ or a series of protease inhibitors. These observations suggest that PI-PLC in broken cell preparations of pancreatic islets may be inactivated via phosphorylation by Ca(2+)-calmodulin-stimulated protein kinase and/or protein kinase C. Inactivation of PI-PLC was reversible. Reactivation started after approx. 2 h incubation, when the concentration of ATP in the homogenate was below 0.15 x 10(-6) M. PI-PLC activity returned to values approx. 25% higher than the initial values. PI-PLC inactivation via phosphorylation by the mentioned protein kinases may constitute a feedback control on the phosphoinositide response, attenuating subsequent diacylglycerol formation and/or Ca2+ mobilization by inositol trisphosphate.
Mol Cell Endocrinol 1991 Nov
PMID:Ca(2+)- and ATP-dependent reversible inactivation of pancreatic islet phosphoinositide-specific phospholipase C activity. 166 65

Tumor necrosis factor-alpha (TNF) is a cytokine involved in the pathogenesis of shock and in granuloma formation, tissue necrosis, and fibrosis, in many organ systems, including the lung. It has been suggested that cells from patients infected by the human immunodeficiency virus (HIV + ve) are primed for TNF release. We postulated that TNF release from the alveolar macrophages (AM) of such patients with lung disease might lead to their observed pulmonary dysfunction. We present data confirming that peripheral blood monocytes (PBM) and demonstrating that AM from HIV + ve patients with pulmonary manifestations show significantly greater TNF production than those from HIV-negative (HIV - ve) subjects. In addition, we found sequentially significant increases in TNF production from AM and PBM of HIV + ve patients with no pathogens detected at bronchoscopy (NB), bacterial pneumonia (BP), and those with Pneumocystis carinii pneumonia (PCP). The overall TNF levels were greater from AM than PBM in all groups other than spontaneous production from HIV - ve subjects. Adherent populations of PBM and AM were incubated for 4 h with lipopolysaccharide (10 micrograms/ml) or control medium alone. Cell-free supernatants were examined for the presence of TNF using an immunoassay. The TNF levels (mean +/- SD) in IU/ml from stimulated PBM of the PCP, BP, NB, and control groups, respectively, were 186 +/- 36, 140 +/- 30, 95 +/- 18, and 55 +/- 10 and the spontaneous levels were 123 +/- 25, 100 +/- 22, 75 +/- 24, and 11 +/- 5.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1991 Aug
PMID:Production of tumor necrosis factor-alpha by blood and lung mononuclear phagocytes from patients with human immunodeficiency virus-related lung disease. 189 44

Huntington's disease (HD) is an inherited neuropsychiatric degenerative process characterized by movement disorder, dementia, and, often, affective disorder (AfD) (seen in 38% of patients). Depression in HD is not just an understandable reaction to fatal illness: 10% of HD patients develop mania; AfD can occur 20 yr before neurological signs; and mood disorders are not randomly distributed, but occur in a subset of HD families. This evidence suggests that AfD in HD relates to brain pathophysiology. With its clear neuropathology, HD is proposed as one model for biological underpinnings of idiopathic AfD. There is striking atrophy and neuronal loss in HD neostriatum, particularly caudate. Caudate has rich connections to the limbic system. It is hypothesized that AfD in HD relates to dysfunction of the part of the neostriatum damaged earliest, dorsal medial caudate. Preliminary studies on neuropathological differences between HD patients with and without AfD are discussed. HD neurochemistry is reviewed, emphasizing the excitotoxin hypothesis, which involves dysfunction of the glutamate neurotransmitter system in HD (especially the NMDA receptor, which contains a channel with a phencyclidine (PCP) binding site). Based on the HD model, it is suggested that the glutamate system (particularly NMDA receptors) be examined in idiopathic AfD.
Mol Chem Neuropathol 1990 Mar
PMID:Huntington's disease as a model for mood disorders. Clues from neuropathology and neurochemistry. 214 28

To learn more about the binding conformation of phencyclidine (PCP) and to arrive at analogues of higher affinity, which may serve as noncompetitive N-methyl-D-aspartate receptor antagonists, eight optically pure PCP analogues were designed with the aid of computer. These compounds represent conformationally constrained versions of PCP in which the motion of the phenyl ring is frozen, thus allowing a determination of the orientation of the phenyl ring relevant to binding. The analogues were synthesized by a Diels-Alder strategy and tested in a radioligand binding assay to evaluate their affinity for the PCP binding site of the N-methyl-D-aspartate receptor complex. One of the analogues was found to bind with nanomolar affinity (IC50 = 19 nM) and to be 73-fold more potent in binding than its enantiomer. These results, which further elucidate the structural determinants of high affinity binding, should aid both in the design of higher affinity molecular probes of the PCP binding site and in the discovery of potential neuroprotective agents.
Mol Pharmacol 1990 Mar
PMID:Structural determinants of affinity for the phencyclidine binding site of the N-methyl-D-aspartate receptor complex: discovery of a rigid phencyclidine analogue of high binding affinity. 215 50

Phencyclidine (PCP) binds with high affinity to the ion channel associated with the NMDA receptor. The binding of the PCP receptor-specific ligand TCP is greatly reduced at temperatures between 2 degrees C and 6 degrees C, at which the plasma membrane is in a rigid state. However, membrane rigidity alone does not appear to cause the reduced TCP binding, since the membrane fluidizing agent A2C did not increase TCP binding at 4 degrees C; instead, it decreased binding at 21 degrees C. This inhibitory effect of A2C on TCP binding was dose dependent and was highly correlated with A2C-induced increases in membrane fluidity. The IC50 of A2C inhibition was 8.9 mM, with a pseudo-Hill coefficient of -0.24. Scatchard analysis demonstrated that this effect was the result of an increase in the apparent KD of [3H]TCP for the PCP receptor, with no effect on the Bmax. These results suggest that the function of the NMDA-PCP receptor complex is impaired by increases in membrane fluidity. These findings may be pharmacologically relevant in understanding the mechanism of action of such agents as general anesthetics and ethanol, which cause increases in plasma membrane fluidity.
J Mol Neurosci 1990
PMID:Effects of membrane fluidity on [3H]TCP binding to PCP receptors. 217 11


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