Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Normal unoperated rats were tested for rotation (i.e., circling behavior) in a spherical "rotometer" and dose-response relationships were generated using d-amphetamine, apomorphine, L-Dopa, haloperidol, and scopolamine. The rotation induced by amphetamine was significantly antagonized by alpha-methyl-p-tyrosine and haloperidol, but not by diethyldithiocarbamate. The rotation elicited by apomorphine was unaffected by alpha-methyl-p-tyrosine. Rotation was not necessarily in the same direction with high and low doses of amphetamine, or amphetamine and apomorphine administered a week apart from each other. Dopaminergic-cholinergic interactions were evident, since pilocarpine antagonized amphetamine-induced rotation whereas scopolamine did not; scopolamine elicited rotation in the same direction as that induced by amphetamine. Left and right striatal dopamine and tel-diencephalic norepinephrine levels were determined in rats injected with various doses of amphetamine and tested for rotation. There were significant bilateral differences in striatal dopamine which were related to the direction of rotation. Since amphetamine was found to be equally distributed to the two sides of the brain, the difference in striatal dopamine appeared to be the neurochemical substrate for rotation in normal rats. These results suggest that normal rats have asymmetrical levels of striatal dopamine as well as an asymmetrical complement of striatal dopamine receptors.
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PMID:Drug-induced rotation in rats without lesions: behavioral and neurochemical indices of a normal asymmetry in nigro-striatal function. 82 60

In cuttlefish, as in selachians and mammals, spermiogenesis is characterized by the double nuclear protein transition histones----intermediate protein (protein T)----protamine (protein Sp). The cuttlefish protein T, which consists of two structural variants phosphorylated at different degrees, is the first invertebrate spermatid-specific protein to be fully characterized and sequenced. The primary structures of these two variants were established from sequence analysis and mass spectrometric data of the proteins and their fragments. T1 and T2 are two highly related proteins of 78 and 77 residues, respectively, which differ only by four conservative substitutions, two inversions Ser in equilibrium with Arg, and the deletion of 1 residue of arginine in variant T2. The asymmetrical distribution of the hydrophobic and basic residues determines two well defined domains: an amino-terminal domain (residues 1-21) devoid of arginine and aromatic residues and containing all the aliphatic hydrophobic residues and a highly basic carboxyl-terminal domain (residues 22-77 or 78) that contains 77% of arginine, all the tyrosine residues, and most of the phosphorylated serine residues present in the protein. The complete structural identity of the basic carboxyl-terminal domain of spermatidal proteins T1 and T2 with the protamine variants Sp1 and Sp2 isolated from cuttlefish spermatozoa strongly suggests that T1 and T2 could be precursors of Sp1 and Sp2, respectively.
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PMID:Cuttlefish spermatid-specific protein T. Molecular characterization of two variants T1 and T2, putative precursors of sperm protamine variants Sp1 and Sp2. 189 25

Under the posterior limb of the anterior commissure, a brain region intercalated between the ventral striatum and the ventral pallidum was previously identified as the interstitial nucleus of the posterior limb of the anterior commissure by de Olmos. This region, referred here as the caudal ventral stratum (VSc), is characterized by a dense plexus of vasoactive intestinal peptide immunoreactive (VIP+) axons. Double-fluorescence immunocytochemical reactions reveal that the dense VIP+ plexus is found in a region also rich in dopaminergic (i.e., tyrosine-hydroxylase immunoreactive) fibers but poor in enkephalinergic terminals. The dense plexuses of VIP+ axons in VSc appear to be contiguous with those in the bed nucleus of stria terminalis (BNST) and the central nucleus of amygdala (CNA). These results support the notion that this VSc region is a part of the "extended amygdala" as proposed recently by Alheid and Heimer, and confirms that its anatomical properties are closer related to the ventral striatum than the ventral pallidum. Electron microscopic analysis reveals that the VIP+ boutons form asymmetrical synapses with dendrites and spines, and symmetrical synapses with somata of unlabeled VSc neurons. The few VIP+ neurons within this area form synapses with many unlabeled axon terminals on both their somata and dendrites. Some VIP+ neurons, however, also form axosomatic and axodendritic synapses with VIP+ boutons.
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PMID:Vasoactive intestinal polypeptide (VIP) immunoreactive elements in the caudal ventral striatum of the rat: a light and electron microscopic study. 193 14

The attempt to use trypsin in order to monitor pH (7.5-9.0) induced beta-lactoglobulin conformation changes has revealed differences in the cleavage of specific sites. The tryptic cleavage of two dibasic X-Lys-Lys-Y sites (Lys 69, 70 and 100, 101) shows slighter predominance of symmetrical cut at pH 7.5 and 8.0. Mostly asymmetrical cleavage yielding two C-terminal lysines can be observed at pH 8.5 and 9.0. Atypical cleavage of the Tyr-20-Ser-21 site, which at pH 9.0 is relatively negligible, increases substantially in pH 7.5-8.5. This implies that Tyr-20 probably is the tyrosine reported to be exposed on the surface of the protein during transformation of beta-lactoglobulin molecule occurring in the studied pH range (Tanford et al. (1959) J. Am. Chem. Soc. 81, 4032-4036).
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PMID:Influence of pH on the structural changes of beta-lactoglobulin studied by tryptic hydrolysis. 200 92

Tyrosine-hydroxylase (TH-IR) and methionine-enkephalin like immunoreactivity (MetE-IR) were analyzed in the lateral septal nucleus (LSN) of the rat from birth (PO) to adulthood. TH-IR labeled specifically the dopaminergic (DA) pericellular arrangements of the LSN, as checked by negative dopamine-beta-hydroxylase and phenylethanolamine-N-methyl transferase-IR. TH-IR and Met-IR processes were present at birth in the medial LSN and extended lateralwards and caudalwards from P0 to P6 to constitute two main DA terminal fields (medial and lateral) surrounding a MetE one. Within these fields, the development of perineuronal baskets followed a similar medial to lateral sequence: DA axons first surrounded a few neuronal cell bodies at P3 in the medial part of the intermediate LSN; at P6, Met-IR axons encircled more laterally located perikarya, and only at P9, some neurons located along the ventricle in the lateral DA field became surrounded. The initial aspect of TH-IR baskets consisting of few axons surrounding the cell body rapidly evolved in a positive network encapsulating the perikaryon and long segments of the proximal dendrites, whereas MetE-IR varicosities remained restricted around the perikaryon and the initial dendritic segments. Ultrastructural study at P14 revealed numerous TH-IR and MetE-IR axosomatic and axodendritic profiles. TH-IR axosomatic varicosities exhibited asymmetrical synapses, whereas MetE-IR ones displayed rare symmetrical contacts. The medio-lateral gradient of development of the perineuronal baskets was parallel to the postnatal neuronal development of the LSN as evaluated by cytological criteria: neuronal density, cell size and Nissl staining. Therefore, the formation of DA and MetE perineuronal arrangements in the LSN does not seem to be subordinate to the nature of the neurotransmitter they contain but related to the level of differentiation of their target neurons. A similar sequential set-up in the development of afferences paralleling the neuronal differentiation is discussed.
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PMID:Postnatal sequential development of dopaminergic and enkephalinergic perineuronal formations in the lateral septal nucleus of the rat correlated with local neuronal maturation. 289 20

The complete sequence for a major Schistosome mansoni eggshell protein gene has been determined from a genomic DNA fragment. The use of an open reading frame encoding a glycine-rich polypeptide was confirmed by in vitro translation of schistosome mRNA in the presence of [3H]glycine and comparison with the amino acid composition of purified, schistosome eggshells. Apart from the extraordinary abundance of glycine and tyrosine which are evenly distributed throughout the polypeptide chain, the most striking features of the deduced amino acid sequence are the presence of five well-conserved tandem repeats of 16-18 residues in the N-terminal region and the asymmetrical distribution of charged residues. Acidic residues (Asp) are confined to the N-terminal region, while basic residues (Lys, His), with the exception of a single histidine, are found in the C-terminal region. A model structure composed of short anti-parallel beta-strands is proposed, in which glycines and residues with small side chains lie within the strands and tyrosines and cysteines are arranged at the bends, where they would be available for cross-linking. Four such strands form one of the tandem repeats which are predicted in turn to form a stack of five closely packed beta-sheets, each of three strands and linked by the more variable fourth strand. The C-terminal region may form a similar but less compact structure. The ordered structure demonstrated by birefringence studies of the schistosome eggshell [Kusel, J. (1970) Parasitology 60, 79-88] could be formed by packing of the polypeptides such that the N-terminal domain contributes counter ions or cross-links to the C-terminal domain of adjacent molecules.
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PMID:Predicted structure of a major Schistosoma mansoni eggshell protein. 291 Dec 80

The tyrosyl-tRNA synthetase from Bacillus stearothermophilus crystallizes as a symmetrical dimer with each subunit having a complete active site. The enzyme-substrate complexes, however, are known to be asymmetrical in solution because the enzyme exhibits half-of-the-sites activity by binding tightly only 1 mol of tyrosine or 1 mol of tyrosyl adenylate per mole of dimer. Evidence is now presented that the unligated enzyme is also asymmetrical in solution. Symmetry was investigated by construction of heterodimers containing one full-length subunit and one truncated subunit, allowing the introduction of different mutations into each monomer. Each dimer is active at only one site, but the site used is randomly distributed between the subunits. Each heterodimer thus consists of two equal populations, one activating tyrosine at a full-length subunit and the other at the truncated subunit. No detectable interconversion is found between active and inactive sites over several minutes either in the absence of substrates or when the enzyme is turning over in the steady state. Kinetic evidence implies that wild-type enzyme is inherently asymmetrical even in the absence of substrate.
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PMID:Asymmetry of tyrosyl-tRNA synthetase in solution. 336 65

We describe improve enzymatic methods for sequencing method for sequencing DNA. They are based on partial digestion of duplex DNA with exonuclease III to produce DNA molecules with 3' ends shortened to varying lengths, followed by repair synthesis to extend and label the 3' ends. After asymmetrical cleavage of the DNA with a restriction enzyme, the labeled products are separated by gel electrophoresis and the sequence read from the autoradiogram. The entire procedures, beginning with unrestricted DNA and followed through gel electrophoresis, takes only one day for sequencing both strands of the DNA molecule. These methods are especially suitable for sequencing DNA cloned in plasmid vectors, and they greatly extend the usefulness of the dideoxynucleotide chain termination method of Sanger et al. (Proc. Natl. Acad. Sci. USA 74, 5463, 1977). Using these methods we have determined the sequence of a 410 base pair fragment which includes the yeast SUP3 tyrosine tRNA gene.
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PMID:New rapid methods for DNA sequencing based in exonuclease III digestion followed by repair synthesis. 628 30

The 20,000 dalton light chain (L2) was isolated from rabbit and chicken striated muscle myosins, and the Ca2+-induced conformational changes of these proteins were investigated. 1) The reaction of thiol groups of L2 with dithiobisnitrobenzoic acid (DTNB), 2) measurements of the UV difference absorption spectrum, 3) measurements of Stokes radius (Rs) by gel filtration and 4) measurements of the ESR spectrum of L2 whose cysteine or tyrosine residues were spin-labeled were used for the structural studies. The effect of Ca2+ on phosphorylated L2 was also investigated. The long axis of chicken L2 was calculated as 136A from the Stokes radius, suggesting that the L2 is an asymmetrical molecule. After the addition of Ca2+ the long axis was reduced to 104 A. The same effect of Ca2+ has been reported with rabbit L2 (Alexis, N.M. & Gratzer, W.B. (1978) Biochemistry 17, 2319-2325). Besides this large shape change, the addition of Ca2+ to L2 induced environmental changes around tyrosine residues and also changes in the reactivity of cysteine residues with DTNB. Ca2+ is supposed to be bound to the N-terminal region of the molecule, while the tyrosine and cysteine residues are located at the C-terminal region, which is probably sterically remote from the N-terminal region. The reason for the remote effect of Ca2+ may be related to the structural rigidity of the L2 molecule. The functions of two properties of L2, Ca2+-binding and phosphorylation, are discussed in relation to muscle contraction.
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PMID:Ca2+-induced conformational changes of 20,000 dalton light chain of vertebrate striated muscle myosins. 631 10

Fluoride is a nucleophilic reagent which has been reported to inhibit a variety of different enzymes such as esterases, asymmetrical hydrolases and phosphatases. In this report, we demonstrate that fluoride inhibits tyrosine kinase activity of insulin receptors partially purified from rat skeletal muscle and human placenta. Fluoride inhibited in a similar dose-dependent manner both beta-subunit autophosphorylation and tyrosine kinase activity for exogenous substrates. This inhibitory effect of fluoride was not due to the formation of complexes with aluminum and took place in the absence of modifications of insulin-binding properties of the insulin receptor. Fluoride did not complete with the binding site for ATP or Mn2+. Fluoride also inhibited the autophosphorylation and tyrosine kinase activity of receptors for insulin-like growth factor I from human placenta. Addition of fluoride to the pre-phosphorylated insulin receptor produced a slow (time range of minutes) inhibition of receptor kinase activity. Furthermore, fluoride inhibited tyrosine kinase activity in the absence of changes in the phosphorylation of prephosphorylated insulin receptors, and the sensitivity to fluoride was similar to the sensitivity of the unphosphorylated insulin receptor. The effect of fluoride-on tyrosine kinase activity was markedly decreased when insulin receptors were preincubated with the copolymer of glutamate/tyrosine. Prior exposure of receptors to free tyrosine or phosphotyrosine also prevented the inhibitory effect of fluoride. However, the protective effect of tyrosine or phosphotyrosine was maximal at low concentrations, suggesting the interaction of these compounds with the receptor itself rather than with fluoride. These data suggest: (i) that fluoride interacts directly and slowly with the insulin receptor, which causes inhibition of its phosphotransferase activity; (ii) that the binding site of fluoride is not structurally modified by receptor phosphorylation; and (iii) based on the fact that fluoride inhibits phosphotransferase activity in the absence of alterations in the binding of ATP, Mn2+ or insulin, we speculate that fluoride binding might affect the transfer of phosphate from ATP to the tyrosine residues of the beta-subunit of the insulin receptor and to the tyrosine residues of exogenous substrates.
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PMID:Inhibitory effect of fluoride on insulin receptor autophosphorylation and tyrosine kinase activity. 768 57


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