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Biomedical subjects

T Hase

Publications and source records attributed to T Hase.

At least 181 records · Page 10Linked to original sources
PubMed1986

Phototropism in Hypocotyls of Radish : I. Isolation and Identification of Growth Inhibitors, cis- and trans-Raphanusanins and Raphanusamide, Involved in Phototropism of Radish Hypocotyls.

Three growth inhibitors which might be involved in phototropism of Sakurajima radish (Raphanus sativus var. hortensis f. gigantissimus Makino) hypocotyls, were isolated as crystalline forms from light-exposed radish seedlings and identified as cis- and trans-raphanusanins and 6-methoxy-2,3,4,5-tetrahydro-1,3-oxazepin-2-one (designated raphanusamide). The cis- and trans-raphanusanins inhibited growth of etiolated radish hypocotyls at concentrations higher than 1.5 micromolar, raphanusamide at concentrations higher than 20 micromolar.

Journal Article↗
PubMed1986

[Intracoronary thrombolysis for high risk patients with acute myocardial infarction].

Fifty-four patients with acute myocardial infarction (AMI) were treated by percutaneous transluminal coronary recanalization (PTCR) within six hours after onset of symptoms or at the time of emergency coronary angiography. Of these, six patients had neither good collaterals nor recanalization, and followed by mechanical failure due to rupture of the left ventricular free wall or interventricular septum in five patients despite antihypertensive therapy. In the remaining 48 patients with good collaterals or recanalization, mechanical failure was statistically infrequent and occurred in only two patients (p less than 0.001). Ninety-four patients treated by PTCR were assessed in terms of mortality, cause of death and their hemodynamic findings. Cardiac deaths occurred in nine patients (9.6%); mechanical failure, in four; and cardiogenic shock due to the occlusion of the left main trunk, in five. Cardiac death was more frequently encountered in the era of the initial stage of PTCR (six of 53 cases: 11.3%) and the main cause was mechanical failure (four of six cases). On the other hand, cardiac death in recent years of PTCR was less (three of 41 cases: 7.3%), and all three had pump failure due to the occlusion of the left main trunk. Risk of mechanical failure was successfully resolved using intra-aortic balloon pumping and beta-blocker in addition to antihypertensive therapy. At the present time, PTCR and other supplementary therapy mentioned above reduced the mortality from mechanical failure and cardiogenic shock, but occlusion of the left main trunk remains an important cause of death in patients with AMI.

Aged↗
PubMed1985

Cloning of the Escherichia coli gene for the stringent starvation protein.

In order to clone the Escherichia coli gene for the stringent starvation protein (SSP), we determined its N-terminal sequence as well as the sequence of two peptide fragments obtained by cyanogen bromide cleavage of the protein. We then chemically synthesized four sets of oligodeoxyribonucleotide mixtures that represented possible codon combinations for parts of these amino acid sequences. The synthetic oligonucleotides were labelled with 32P at their 5'-termini and used as hybridization probes to detect DNA fragments containing the complementary sequences. Genomic Southern hybridization of E. coli chromosomal DNA gave up to ten DNA fragments hybridizing with each probe but only a few hybridized with two or more of the probes. The latter fragments were cloned in pBR322. By determining partial base sequences with a rapid method and examining proteins encoded by the DNA fragments, we were able to show that we had isolated a clone containing the complete SSP structural gene.

Amino Acid Sequence↗
PubMed1984

A 70-kd protein of the yeast mitochondrial outer membrane is targeted and anchored via its extreme amino terminus.

The major 70-kd protein of the yeast mitochondrial outer membrane is made on cytosolic ribosomes and imported into the outer membrane without proteolytic cleavage. We have attempted to identify the sequences which target the protein to the mitochondria and which permanently anchor it to the lipid bilayer of the outer membrane. By manipulating the cloned gene we have deleted 13 different regions throughout the polypeptide; in addition, we have fused amino-terminal regions of different length to beta-galactosidase. Each altered gene was introduced into yeast and the intracellular fate of the corresponding polypeptide product was determined by subcellular fractionation. All the information for targeting and anchoring the 70-kd protein (617 amino acids) was contained within the amino-terminal 41 amino acids. When this entire region was deleted, the protein was recovered with the cytosol fraction. However, several restricted deletions within this amino-terminal region appeared to affect targeting and anchoring differentially: most of the altered protein remained in the cytosol but a small fraction was misrouted into the mitochondrial matrix space. We suggest that targeting is mediated by a region which includes the 11 amino-terminal amino acids whereas the permanent membrane anchor is provided by a typical transmembrane sequence between residues 9 and 38.

Amino Acid Sequence↗
PubMed1984

Structural homologies between the amino acid sequence of Clostridium pasteurianum MoFe protein and the DNA sequences of nifD and K genes of phylogenetically diverse bacteria.

The complete amino acid sequence of the larger (alpha-) subunit and about 70% of the total sequence of the smaller (beta-) subunit of the MoFe protein from Clostridium pasteurianum was determined by analyses of peptides derived from BrCN cleavage and by digestions with trypsin, staphylococcal protease and lysylendo-peptidase of the separated subunits. The alpha-subunit has 529 amino acid residues, giving an Mr value of 58 774. This is the first complete sequence for the alpha-subunit of an isolated MoFe protein. In comparing the sequences of both subunits to those from other sources, 5 out of 9 cysteines in the alpha-subunit and 3 out of 6 in the beta-subunit are invariant, thus suggesting a function as ligands to FeS and MoFeS clusters in the MoFe protein. All of these cysteines are located in the amino terminal halves of both subunits.

Amino Acid Sequence↗
PubMed1984

Characterization of a mini plasmid isolated from Shigella sonnei.

A multicopy plasmid, 2.1 kb in size, was isolated from Shigella sonnei and named pKYM. This plasmid is cryptic and isolated along with pKY-1, a ColE1-like plasmid. In this paper, we report the physical map of pKYM and some characters required for its multiplication. The replication of the plasmid DNA does not require DNA polymerase I but depends on protein(s) produced by itself. The plasmid is poorly mobilized by the F factor.

Cloning, Molecular↗
PubMed1984

Effect of the replacement of pRoR promoter of lambda dv plasmid by lac promoter on the synthesis of DNA.

Derivatives of lambda dv whose pRoR promoter was replaced by lactose operon (lac promoter) were constructed and cloned in pBR322 plasmid. They were named pLOP-1, 2, and 3, and their structures are shown in Fig. 1. These plasmids were introduced into Escherichia coli (E. coli) lac iq and the effect of the inducer of lac promoter on the synthesis of plasmid DNA was examined. The synthesis of pLOP-2 or 3 DNA was strongly stimulated. pLOP-1, however, responded poorly to the inducer. Plasmids pLOP-2 and 3 were not segregated evenly into daughter cells after the induction and most of the progeny cells did not receive the plasmid. The synthesis of plasmid DNA after induction depended on the function of O and P genes and was inhibited by the addition of rifampicin and chloramphenicol. Most of the plasmid DNA synthesized after the induction cosedimented with the folded host chromosomal complex, suggesting an unusual structure of the DNA. When the inducer was removed, normal segregation of the plasmid resumed and the copy number of plasmid DNA decreased to the original level.

Cloning, Molecular↗
PubMed1984

Pharmacokinetic studies of mabuterol, a new selective beta 2-stimulant. I: Studies on the absorption, distribution and excretion in rats.

Pharmacokinetic studies on absorption, distribution, excretion and placental transfer of the beta-sympathomimetic 14C-labelled dl - 1 - (4 - amino - 3 - chloro - 5 - trifluoromethyl-phenyl)-2-tert.-butylamino-ethanol hydrochloride (mabuterol) have been carried out in rats. Mabuterol was easily absorbed from the whole length of the small intestine in a study in situ with the gastro-intestinal ligated loop technique. The blood and tissue levels of radioactivity reached the maximum within 1 h after oral administration. Concerning tissue distribution (excluding the digestive tract) after oral administration, the radioactivity in the liver, lung, kidney and several secretory organs was considerably higher than that in the blood. The levels of radioactivity in these tissues continued at almost the same levels for 2-6 h after oral administration, resulting from a slow gastric emptying of the radioactivity. The whole-body autoradiograms obtained after intravenous administration revealed the secretion of the radioactivity into the stomach. The radioactive concentration in the CNS was much lower than that in the principal organs with either route of administration. About 60% and 26% were excreted into urine and feces, respectively, within 24 h after oral administration. Although about 22% was excreted into bile within 24 h after intravenous administration, no other evidence of enterohepatic circulation was observed. The multiple oral administration of 14C-mabuterol indicated no, appreciable accumulation in the tissues of rats. A placental transfer in the pregnant rats in the last stage of gestation was not significant.

Adrenergic beta-Agonists↗
PubMed1983

Complete amino acid sequence of an alpha-amylase inhibitor in wheat kernel.

We recently purified a new alpha-amylase inhibitor (called 0.53-inhibitor according to its mobility on polyacrylamide gel electrophoresis, at pH 8.5, relative to Bromophenol blue (taken as 1), under the conditions described by O'Donnell, M.D. and McGeeney, K.F. (1976) Biochim. Biophys. Acta 422, 159-169)) from wheat kernel, which has 500-times greater inhibitory activity towards human salivary amylase than towards human pancreatic amylase (Maeda, K., Takemori, Y. and Oka, O. (1982) Agric. Biol. Chem. 41, 2873-2875). Elucidation of the primary structure and structural comparison with other amylase inhibitors are essential to understand the mechanism of the selective inhibitory behavior of 0.53-inhibitor. The complete amino acid sequence of 0.53-inhibitor has been determined after cleaving the protein with CNBr and trypsin separately. 0.53-Inhibitor is composed of two identical subunits with 124 amino acid residues and contains nine cysteine residues in each subunit. Comparison of the sequence of 0.53- and 0.28-inhibitor, which is a major alpha-amylase inhibitor in wheat, with Mr 12 000, of monomeric form, shows high sequence homologies of nine cysteine regions, but significant differences are evident.

Amino Acid Sequence↗
PubMed1983

Import of proteins into mitochondria: a 70 kilodalton outer membrane protein with a large carboxy-terminal deletion is still transported to the outer membrane.

The yeast mitochondrial outer membrane contains a major 70-kd protein which is coded by a nuclear gene. Two forms of this gene were isolated from a yeast genomic clone bank: the intact gene, and a truncated gene which had lost a large part of its 3' end during the cloning procedure. Upon transformation into yeast, both the intact and the truncated gene are expressed; the truncated gene generates a shortened protein missing 203 amino acids from the carboxy-terminus. This truncated polypeptide reacts with a monoclonal antibody against the authentic 70-kd protein and is transported to the mitochondrial outer membrane. By integrative transformation, we have constructed a yeast mutant which lacks the 70-kd protein and is unable to adapt to growth on a nonfermentable carbon source at 37 degrees C. This phenotypic lesion can be corrected by transforming the mutant with the intact, but not the truncated gene. The carboxy-terminal sequence of 203 amino acids is thus necessary for the function of the protein, but not for its targeting to the mitochondrion.

Base Sequence↗
PubMed1983

Import of proteins into mitochondria: nucleotide sequence of the gene for a 70-kd protein of the yeast mitochondrial outer membrane.

The nucleotide sequence of the yeast chromosomal gene coding for the 70-kd protein of the mitochondrial outer membrane was determined. The deduced amino acid sequence of the protein agrees with the experimentally determined size and amino acid composition of the purified protein and correctly predicts the fragments obtained by cleaving the protein at its single tryptophan residue. The deduced NH2-terminal sequence features an uninterrupted stretch of 28 uncharged amino acids flanked on both sides by basic amino acids. By sequencing a truncated version of the gene it was found that the corresponding polypeptide product lacks the 203 carboxy-terminal amino acids of the authentic 70-kd protein. As shown in the accompanying paper, this protein fragment still becomes attached to the mitochondrial outer membrane in vivo.

Amino Acid Sequence↗
PubMed1983

Amino acid sequence studies of the light subunit of methylamine dehydrogenase from Pseudomonas AM1: existence of two residues binding the prosthetic group.

The methylamine dehydrogenase from Pseudomonas AM1 is a tetramer composed of two subunits, light(L)- and heavy-subunits. The amino acid sequence of the L-subunit was determined by sequence analyses of trypsin, chymotrypsin, staphylococcal protease, and thermolysin peptides of Cm-protein. The subunit consisted of a single polypeptide chain of 129 amino acid residues, with alanine and serine at the amino(N)- and carboxyl(C)-terminus, respectively. Yellow-colored peptides containing a prosthetic group were composed of two polypeptide chains and the prosthetic group was covalently bound to two residues at positions 55 and 106, which could not be identified yet. The molecular weight of the subunit was 13,500 excluding the binding residues and the prosthetic group. Various structural features are discussed.

Amino Acid Sequence↗
PubMed1983

Structure of the extracellular ferredoxin from Rhodospirillum rubrum: close similarity to clostridial ferredoxins.

The amino acid sequence of an [8Fe-8S] ferredoxin isolated from the culture medium of Rhodospirillum rubrum, a photosynthetic purple non-sulfur bacterium, was determined by a combination of various conventional procedures. The sequence was A-Y-K-I-E-E-T-C-I-S-C-G-A-C-A-A-E-C-P-V-N-A-I-E-Q-G-D-T-I-F-V-V-N-A-D-T-C-I-D-C - G-N-C-A-N-V-C-P-V-G-A-P-V-A-E (55 amino acid residues). It lacked methionine, leucine, histidine, arginine, and tryptophan. The molecular weight was calculated to be 5,568 excluding iron and sulfur atoms. The distribution of 8 cysteine residues was exactly the same as that of clostridial-type ferredoxin, suggesting retention of the duplication of the bacterial ancestral ferredoxin gene. The extracellular ferredoxin of R. rubrum was compared with other ferredoxins observed in closely related photosynthetic bacteria and the evolutionary significance of this ferredoxin is discussed.

Amino Acid Sequence↗
PubMed1983

Partial amino terminal sequence of the precursor of mitochondrial ATPase inhibitor protein synthesized with mRNA partially purified by gel permeation chromatography.

Messenger RNA coding mitochondrial ATPase inhibitor protein, a small peptide comprised of 63 amino acid residues, was separated from a large quantity of mRNAs of larger molecules by high speed gel permeation chromatography. Messenger RNA coding a small stabilizing factor of inactivated F1F0-ATPase complex, which is also comprised of 63 amino acids, was recovered in the same fraction as the ATPase inhibitor, whereas mRNA for a large stabilizing factor with an apparent molecular weight of 15,000 was recovered in a fraction of slightly larger molecules. ATPase inhibitor precursor labeled with various kinds of radioactive amino acids was prepared separately by cell-free translation with the purified mRNA, and the amino terminal sequence of the precursor was examined. It was demonstrated that an extra peptide of 21 amino acid residues, including 5 leucine, 4 serine, 1 glycine, and 1 methionine residues, is located at the amino terminus of the ATPase inhibitor precursor.

Amino Acid Sequence↗
PubMed1983

Main chain fold of a [2Fe-2S]ferredoxin I from Aphanothece sacrum at 2.5 A resolution.

Crystal structure analysis of a [2Fe-2S]ferredoxin I from Aphanothece sacrum, a blue green alga, was carried out at 2.5 A resolution. The phase angle of each reflection was determined by the single isomorphous replacement method coupled with the anomalous dispersion effect for the uranium derivative. The four molecules in an asymmetric unit were clearly seen in a 3.9 A electron density map. The main chains of three molecules were traced at 2.5 A resolution. The structure of the remaining one molecule, however, remains unknown because of the poor electron density of the corresponding region. The three main chain folds exhibit the same topology as that in Spirulina platensis. The structural similarity between A. sacrum and S. platensis ferredoxins, whose amino acid sequences are different from each other by about 30%, strongly suggests that all plant-type ferredoxins have the same main chain fold.

Amino Acid Sequence↗
PubMed1983

Classification of iron-sulfur cores in ferredoxins by 1H nuclear magnetic resonance spectroscopy.

A 1H nuclear magnetic resonance (NMR) study was carried out on various ferredoxins which possess one of three types of iron-sulfur clusters, (2Fe-2S), (3Fe-3S), or (4Fe-4S). In the isolated form, (2Fe-2S) ferredoxins from spinach (Spinacea oleracia), pokeweed (Phytolacca americana), a blue-green alga (Spirulina platensis), and a halobacterium (Halobacterium halobium) exhibited two broad resonances common in chemical shift at the region downfield of 10 ppm. In their reduced forms, seven contact-shifted resonances appeared spread over 30 ppm. Although the positions of the contact-shifted resonances in the reduced state differed among the four, a common trend in the temperature dependence of their resonance positions was recognized. Two (4Fe-4S) ferredoxins from Bacillus stearothermophilus and Bacillus thermoproteolyticus exhibited almost indistinguishable spectral patterns in both the oxidized and reduced forms. The ferricyanide-treated ferredoxins of B. stearothermophilus and B. thermoproteolyticus showed characteristic contact-shifted resonances distinct from the spectra of the original (4Fe-4S) ferredoxins. This corresponds to the recent finding of the interconversion of (4Fe-4S) and (3Fe-3S) clusters with ferricyanide in the ferredoxin. Based on our data together with reported NMR data on other ferredoxins, contact-shift resonances of three types of clusters were tabulated. The reliability of NMR classification increases when we compare the NMR spectra of a ferredoxin with the classification standards at the two redox states. Moreover, not only the absolute values of the chemical shifts of contact-shifted resonances but also their temperature dependence give distinctive information applicable to iron core identification.

Azotobacter↗