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Biomedical subjects

M Miwa

Publications and source records attributed to M Miwa.

At least 253 records · Page 14Linked to original sources
PubMed1985

Structure of the pX protein deduced from the nucleotide sequence of a cDNA clone of pX mRNA in cells infected with human T-cell leukemia virus type I.

A splice donor site of pX mRNA of human T-cell leukemia virus type I was elucidated by analyzing a cDNA clone of poly A+ RNA isolated from cat fibroblast cells infected with the virus. The donor site was located near the 5' end of the env gene. The putative N-terminal amino acid sequence of the pX protein was deduced to be Met-Ala-His---.

Amino Acid Sequence↗
PubMed1985

Platelet-activating factor-binding protein in human serum.

The occurrence of a kind of protein (PBP) with stronger PAF-binding ability than albumin was shown in human serum. The molecular weight of PBP was approximately 160K to 180K. PBP seemed to be a pentamer composed of five 32K subunits. PAF bound to PBP revealed platelet aggregation and was resistant to acetyl-hydrolase. PAF synthesized in neutrophils stimulated with the ionophore A23187 was released by PBP from cells.

Animals↗
PubMed1985

Myristylation of gag protein in human T-cell leukemia virus type-I and type-II.

We found that p19gag of HTLV-I and p23gag of HTLV-II are myristylated. The p28, which is immunologically cross-reactive with monoclonal antibody against p19gag of HTLV-I was also shown to be myristylated in the HTLV-I-infected cell lines MT-2 and HUT102. However, no myristylated p28 was found in HTLV-II-infected cell lines, Mo and Ton1.

Antibodies, Monoclonal↗
PubMed1984

Immortalization of peripheral blood lymphocytes of cats by human T-cell leukemia virus.

Peripheral blood lymphocytes of domestic cats were co-cultivated with lethally irradiated MT-2 cells, which produced human T-cell leukemia virus type 1 (HTLV-I). Two cat lymphoid cell lines, CaL-1 and CaL-2, established and maintained without exogenously added T-cell growth factor, were characterized after more than 6 months of cultivation. These cells grew in suspension, had a chromosome number of 38 and lacked cytoplasmic and surface immunoglobulins. CaL-2 cells formed E-rosettes. Both cell lines harbored HTLV genomes but not human Alu family sequences, which are highly repetitious in the human genome, suggesting that transfer of human DNA fragments was not necessary for their immortalization or transformation. HTLV antigens were detected in CaL-1 and CaL-2 cells by indirect immunofluorescence assay. CaL-1 and CaL-2 cells both expressed viral proteins with apparent molecular weights of 53 kd, 24 kd and 19 kd, and CaL-2 cells also expressed 28 kd and 20 kd proteins. Reverse transcriptase activity was detected in culture fluid of CaL-2 cells, but not of CaL-1 cells. CaL-2 cells but not CaL-1 cells had syncytium-induced activity. These findings indicated that lymphocytes of cats, especially T lymphocytes, were susceptible to infection with HTLV and to immortalization by HTLV.

Animals↗
PubMed1984

Monoclonal antibodies to poly(adenosine diphosphate ribose) recognize different structures.

Two hybridomas producing monoclonal antibodies to poly(adenosine diphosphate ribose) [poly(ADP-Rib)] were established. One antibody, 10H (IgG3, kappa), bound to most of the poly(ADP-Rib) preparation, which consisted of molecules of various sizes of more than 20 ADP-Rib residues. The binding of this antibody was inhibited by not only poly-(ADP-Rib) but also a monomer unit of poly(ADP-Rib), Ado(P)-Rib-P. The sites protected by antibody 10H were isolated and analyzed by hydrolysis with alkaline phosphomonoesterase and then snake venom phosphodiesterase. The sites contained the same amounts of monomer units and branched portions [Ado(P)-Rib(P)-Rib-P] as the original poly(ADP-Rib) molecules but a lower average number of branched portions per molecule than in the original molecules. The other antibody, 16B (IgM, lambda), reacted with only 50% of the radioactive poly(ADP-Rib), and its binding was not inhibited by a monomer unit. This antibody protected 25% of all the poly(ADP-Rib) molecules from hydrolysis by snake venom phosphodiesterase. The protected sites contained twice as many branched portions per molecule as the original poly(ADP-Rib) molecules. These results show that the two monoclonal antibodies recognize different structures of poly-(ADP-Rib); 10H antibody recognizes the linear structure with ribose-ribose linkages, and 16B antibody may recognize specific structures, including the branched portions of poly-(ADP-Rib).

Animals↗
PubMed1984

Effects of various kinds of stimulation on ornithine decarboxylase activity in superior cervical sympathetic and nodose ganglia of rats.

Levels of cyclic nucleotides and ornithine decarboxylase (ODC) activity were examined following the application of various kinds of stimuli to superior cervical sympathetic ganglia (SCG), nodose ganglia, and vagus nerve fibers excised from the rat. The level of cyclic GMP in the SCG rose rapidly to about 4.5- to 7.5-fold the unstimulated control with 10 min of incubation after applications of preganglionic electrical stimulation (10 Hz), acetylcholine (ACh; 1 mM), or high extracellular K+ ( [K+]0, 70 mM). The cyclic GMP level in nodose ganglia was increased less than in the SCG by either ACh or high [K+]0 but was not affected by ACh in vagus fibers. Cyclic AMP in the SCG was also increased about 4- to 5.5-fold over the control within 10 min with the addition of ACh, norepinephrine (NE; 0.05 mM), or high [K+]0. Although NE caused a small increase in cyclic AMP, neither ACh nor high [K+]0 produced any appreciable change in nodose ganglia or vagus fibers. The ODC activity in the SCG was increased by preganglionic stimulation of 3- to 4-hr duration but not by a shorter period. A similar change in ODC activity was caused by the addition of oxotremorine (1 mM), isoproterenol (0.1 mM), NE, cyclic AMP (1 mM), or dibutyryl cyclic GMP (1 mM). The effect was exaggerated by the further addition of 3-isobutyl-1-methylxanthine (IBMX), a phosphodiesterase inhibitor. The increase in ODC activity caused by ACh was abolished by a muscarinic cholinergic antagonist, atropine (0.01 mM), and following axotomy for a week, but not by a nicotinic antagonist or by denervation in the SCG. A similar increase in ganglionic ODC activity by NE was inhibited by an adrenergic blocker, propranolol (0.01 mM), and following axtotomy for a week, but not by denervation. Cholinergic or adrenergic stimulation did not cause an increase in ODC activity in nodose ganglia or vagus fibers. These results suggest that the stimulation-induced increase in ODC activity occurs in postganglionic neurons rather than in satellite glial cells and is mediated by muscarinic cholinergic or adrenergic receptors. The process appears to involve cyclic nucleotide-mediated protein biosynthesis in the SCG.

Animals↗
PubMed1984

Nucleotide sequence of the 3' region of an infectious human T-cell leukemia virus type II genome.

The nucleic acid sequence of the 3' region of human T-cell leukemia virus type II (HTLV-II) proviral DNA was determined using a HTLV-II proviral clone that could be recovered as infectious, transforming virus. The sequence data indicate a region of unknown function of approximately equal to 1.6 kilobase pairs in the 3' region, analogous to the X region previously identified in human T-cell leukemia virus type I (HTLV-I). Three overlapping open reading frames are present in the X region of HTLV-II. One of these open reading frames, Xc, is most likely to encode a protein product, because it has greater predicted amino acid sequence homology (78%) with the X-IV region of HTLV-I and a greater percentage of its base differences with X-IV at the third nucleotide position of codons than do the other open reading frames. Sequences of the X-region that include the open reading frames are conserved in two deletion mutants of HTLV-II, which are associated with a subline of Mo cells with a decreased dependence on fetal bovine serum.

B-Lymphocytes↗
PubMed1984

Nucleotide sequence analysis of the long terminal repeat of human T-cell leukemia virus type II.

The nucleotide sequence of the human T-cell leukemia virus type II (HTLV-II) long terminal repeat (LTR) and its surrounding regions were determined. Our results show the following structural features: (i) the LTR is 763 base pairs (bp) in length and consists of 314 +/- 1 bp of region U3, 248 +/- 1 bp of region R, and 201 bp of region U5; (ii) the terminal nucleotides in the LTR form an inverted repeat of T-G.....C-A; (iii) 6-bp direct repeats of cellular sequences flanking the provirus were present; and (iv) the putative functional signals for initiation or termination of viral RNA synthesis were identified. Comparison of the HTLV-II LTR sequence with that previously published for adult T-cell leukemia virus (ATLV; HTLV-I) shows that the LTRs are distinct. Some small regions are conserved between HTLV-II and ATLV, involving sequences important for transcription and a sequence of 21 nucleotides repeated three times in U3. This 21-bp repeat may be important in regulating viral transcription in lymphoid cells.

Base Sequence↗
PubMed1984

A circular dichroism study on thermal denaturation of a dimeric globular protein, Streptomyces subtilisin inhibitor.

Thermal denaturation of Streptomyces subtilisin inhibitor was studied by means of circular dichroism (CD) measurements in the far-UV and near-UV regions. The denaturation was found to be largely reversible; the partial irreversibility was associated with a slight loss of the inhibitory activity. Difference CD spectra in the far-UV region clarified the existence of two distinct steps in the thermal transition of the secondary structure. The first step below 80 degrees C is attributable to a partial conformational change in the alpha-helix portion, whereas the second step between 80 degrees C and 94 degrees C is attributable to a major conformational change involving the beta-sheet portion. On the assumption that the major denaturation involves dissociation of the SSI into its subunits, the enthalpy and entropy changes were determined to be 216 kcal X mol-1 and to be 603 cal X deg-1 X mol-1, respectively.

Bacterial Proteins↗
PubMed1984

Studies on phospholipase A inhibitor in blood plasma. I. Purification and characterization of phospholipase A inhibitor in bovine plasma.

Phospholipase A inhibitor was found in bovine, human and porcine plasma. The inhibitor was purified about 300-fold from bovine plasma by ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 gel filtration and anti-BSA antibody-agarose column chromatography to remove albumin. The purified material was homogeneous as judged by immunoelectrophoresis and 0.7% agarose-2% polyacrylamide gel electrophoresis. The inhibitor suppressed not only rat and human plasma phospholipase A2 activity, but also purified Mamushi (Agkistrodon halys blomhoffi) venom phospholipase A2-II. Bovine plasma inhibitor was shown to be a lipoprotein containing phosphatidylcholine, sphingomyelin, cholesterol ester, and triacyl glycerol as major lipid components. The molecular weight of the native inhibitor was nearly the same as that of bovine plasma high density lipoprotein (HDL) when determined by the gel filtration method. The molecular weights of two subunits of the inhibitor observed on polyacrylamide gel electrophoresis in the presence of SDS were about 10K and 42K. The anti-inhibitor antiserum obtained from rabbits immunized with the highly purified inhibitor cross-reacted with bovine plasma alpha-lipoprotein (HDL). The lipid composition of the inhibitor was similar to that of HDL, but apoinhibitor and apoHDL were different in molecular weight and solubility in various buffers.

Animals↗
PubMed1984

Effects of various forms of stimulation on the content of enolase isozymes and S-100 protein in superior cervical sympathetic ganglia excised from rats.

Contents of the three forms (alpha alpha, alpha gamma, and gamma gamma) of enolase isozymes and S-100 protein in superior cervical sympathetic ganglia (SCG) excised from rats were determined by the sensitive method of enzyme immunoassay, after application of various forms of stimulation, during incubation for 3 h at 37 degrees C in vitro. The amounts of the three forms of enolase isozymes and of S-100 protein in the SCG were not altered by preganglionic or postganglionic stimulation (10 Hz) or by the addition of acetylcholine (1 mM) or a high concentration of K+ (70 mM) to the incubation medium. Norepinephrine (NE; 50 microM), as well as isoproterenol (200 microM) or 3,4-dihydroxy phenylethylamine (dopamine; 200 microM), increased the ganglionic alpha alpha and alpha gamma enolase content to 1.5 to 2.0 times the control level, whereas NE tended to slightly decrease the gamma gamma enolase content. The increase in the alpha isozymes did not appear until after 2 to 3 h of incubation with this agent as a result of an increase in protein synthesis. Propranolol, an adrenergic antagonist, partly inhibited the NE-induced increase in both alpha alpha and alpha gamma enolases. NE and its agonists also considerably increased the S-100 protein level in the SCG; however, the effect developed within half an hour of incubation as a result of the conversion of the bound S-100 protein to the water-soluble form, and did not greatly increase thereafter. Cyclic AMP (1 mM) produced the same kind of increase in the ganglionic S-100 protein content as NE did.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1984

Effects of denervation and axotomy on nervous system-specific protein, ornithine decarboxylase, and other enzyme activities in the superior cervical sympathetic ganglion of the rat.

The time courses of changes of three enolase isozymes (alpha alpha, alpha gamma, and gamma gamma), S-100 protein, 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), ornithine decarboxylase (ODC), beta-galactosidase, and glucose-6-phosphate dehydrogenase (G6PDH) were examined from 1 to 14 days after cutting of the preganglionic nerve (denervation) or the postganglionic nerve (axotomy) of the superior cervical sympathetic ganglion (SCG) of the rat. The wet weight and protein content in the axotomized SCG increased continuously, to nearly twice those of the denervated SCG for 1-2 weeks after the operations. Among enolase isozymes in the SCG, neuron-specific gamma gamma-enolase decreased rapidly after denervation and stayed at a low level for 2 weeks, whereas the isozyme remained almost unchanged after axotomy. On the contrary, ganglionic alpha alpha-enolase and the alpha gamma-hybrid form increased remarkably to reach a maximum at the second day after axotomy, and remained above control for 1 to 2 weeks; these two enolase isozymes showed little change after denervation. Denervation caused a much larger increase than did axotomy in the ganglionic S-100 protein, an astrocyte-specific protein, during the first week after the operation, while the protein content decreased after 2 weeks of either denervation or axotomy. CNPase, a myelin-associated enzyme, rose suddenly 2 days after axotomy, and remained at a rather high level compared with the denervated ganglion, which showed little variation.(ABSTRACT TRUNCATED AT 250 WORDS)

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1984

Detection of pX proteins in human T-cell leukemia virus (HTLV)-infected cells by using antibody against peptide deduced from sequences of X-IV DNA of HTLV-I and Xc DNA of HTLV-II proviruses.

A 41-kilodalton protein was detected in four human T-cell leukemia virus type I (HTLV-I)-infected cell lines, a 68-kilodalton glycoprotein in MT-2 cells, and a 38-kilodalton protein in an HTLV-II-infected cell line by using antibody against a synthetic dodecapeptide, a portion of the polypeptide deduced from the nucleotide sequence of the X regions of HTLVs.

Animals↗