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Biomedical subjects

T Hase

Publications and source records attributed to T Hase.

At least 199 records · Page 11Linked to original sources
PubMed1983

A new growth inhibitor, pisumin, involved in light inhibition of epicotyl growth of dwarf peas.

A new growth inhibitor, tentatively named pisumin, which increased under red light and remained at initial level or decreased when dwarf pea (Pisum sativum L. cv Progress No. 9) seedlings were transferred from red light to dark, has been isolated in the form of a colorless powder from light-exposed epicotyls of dwarf peas, and characterized partially as an aliphatic carboxylic acid (molecular weight 284) by spectrometric analyses.Exogenous pisumin inhibited the growth of epicotyl segments of dwarf peas at concentrations higher than 0.1 millimolar in the dark.

Journal Article↗
PubMed1983

Growth pattern of Rickettsia tsutsugamushi in irradiated L cells.

Irradiated L cells infected with Rickettsia tsutsugamushi were studied under the electron microscope to define the morphological growth pattern of the organism. For 2 days after inoculation, no rickettsiae were found either extra- or intracellularly; after 2 days multiple rickettsiae appeared within the host cells without morphological evidence of their entry. These observations showed that the rickettsiae within the cell were assembled in situ by segregation of portions of the granular cytoplasm and subsequent internal differentiation and surface membrane assembly of the segregated bodies. The protoplasmic (P) bodies, which seemed to be formed by shedding infected-cell granular cytoplasm, consistently appeared on the surface and within the phagosomes of the host cells. Rickettsiae were occasionally seen entering host cells in the later phase of infection; these were apparently the ones assembled within the P bodies. This suggested that the P bodies, and not the rickettsiae, were the major infectious particles that transmitted the rickettsial genetic substance among the host cells. On the basis of the present morphological observations, viral-type multiplication for R. tsutsugamushi is proposed.

Animals↗
PubMed1983

Assembly of Rickettsia tsutsugamushi progeny in irradiated L cells.

In the assembly of Rickettsia tsutsugamushi progeny in irradiated L cells, nascent forms first appear as undemarcated foci in the host cell granular cytoplasm, in which electron-lucent filamentous (f) and electron-dense granular (g) areas differentiate. Morphological observations indicated that the assembly involves formation of a filamentous network in the f area, manufacture of rickettsial ribosomes in the g area, and formation of mildly electron-dense fuzzy zones, along which a double membrane assembles.

Animals↗
PubMed1983

Amino acid sequence of a ferredoxin from Bumilleriopsis filiformis, a yellow-green alga: relationship with red algae, protoflorideophyceae, and filamentous blue-green algae.

The amino acid sequence of a [2Fe-2S] ferredoxin isolated from Bumilleriopsis filiformis, a yellow-green alga, was determined by using conventional techniques. It consisted of 98 amino acid residues with a microheterogeneity at the amino-terminus: Ala/Glu-Thr-Tyr-Ser-Val-Thr-Leu-Val-Asn-Glu-Glu-Lys-Asn-Ile-Asn-Ala-Val- Ile- Lys-Cys-Pro-Asp-Asp-Gln-Phe-Ile-Leu-Asp-Ala-Ala-Glu-Glu-Gln-Gly-Ile-Glu- Leu- Pro-Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Thr-Cys-Ala-Gly-Lys-Val-Leu-Ser- Gly- Thr-Ile-Asp-Gln-Ser-Glu-Gln-Ser-Phe-Leu-Asp-Asp-Asp-Gln-Met-Gly-Ala-Gly- Phe- Leu-Leu-Thr-Cys-Val-Ala-Tyr-Pro-Thr-Ser-Asp-Cys-Lys-Val-Gln-Thr-His-Ala- Glu- Asp-Asp-Leu-Tyr. No prominent structural feature was noted in this ferredoxin in comparison with other homologous ferredoxins. From the structural comparison, B. filiformis was placed taxonomically close to filamentous blue-green algae and red algae.

Amino Acid Sequence↗
PubMed1983

Ferredoxin from Aphanothece halophitica, a unicellular blue-green alga: close relationship to ferredoxins from filamentous blue-green algae and phylogenetic implications.

The amino acid sequence of a ferredoxin from a unicellular blue-green alga, Aphanothece halophitica, was established by the conventional methods. Total number of residues was 98 lacking only tryptophan. A most probable phylogenetic tree was constructed for 19 algal ferredoxins on the basis of an amino acid difference matrix made from the sequence comparison. A. halophitica has been classified as a unicellular blue-green alga in the same genus to which Aphanothece sacrum belongs, but the tree indicates A. halophitica ferredoxin to be very close to those of the members of filamentous blue-green algae. The tree divides prokaryotic and eukaryotic algal ferredoxins into several groups, suggesting that the ferredoxin phylogenetic tree reflects the evolutionary trails of various algae, which is also reflected in the structural characteristics, particularly in the presence of gaps. Other notable features are presented in considering algal taxonomy.

Amino Acid Sequence↗
PubMed1982

Bacteriophage lambda initiators: preparation from a strain that overproduces the O and P proteins.

A recombinant plasmid was constructed which carries bacteriophage lambda initiator genes O and P under control of tandemly arranged PL and PR promoters. These promoters were repressed by a thermosensitive repressor, cI857, at low temperature, but became active when the culture was incubated at 42 degrees C. Upon elevation of the temperature, the O and P proteins were overproduced to the extent that they constituted several per cent of the total E. coli cellular proteins. Both the O and P proteins have been purified to apparent homogeneity, and were shown to consist of 298 and 233 amino acid residues, respectively. The amino acid composition and the terminal partial amino acid sequence of each protein were determined. Through these analyses, the locations of the O and P genes in the known lambda DNA sequence were determined. The termination codon for the O gene overlaps with the initiation codon for the P gene. The purified O protein binds specifically to the replication origin of lambda (lambda ori) in accordance with our previous observations. The purified P protein inhibits an ATPase activity of dnaB protein.

Adenosine Triphosphatases↗
PubMed1982

Evidence for histamine-mediated inhibition of monocyte chemotaxis in atopic dermatitis.

Leukocyte chemotaxis was studied in 11 patients with severe childhood onset atopic dermatitis at a time when their disease was relatively quiescent. Pyoderma had been an important complication of the dermatitis in these patients. The chemotactic responsiveness of patient neutrophils and monocytes was on the average not significantly different from that of healthy control subjects, although three patients were identified who had significantly impaired responses. No correlation between IgE levels and leukocyte chemotaxis was observed. Because excessive amounts of histamine have been recovered from the skin of patients with atopic dermatitis, we evaluated the effects of histamine on the chemotactic responsiveness of leukocytes from these patients. Histamine caused a small dose-related increase in chemotaxis of neutrophils from both patients and control subjects (10(-7)M to 10(-5)M histamine). In contrast, histamine had no effect on the chemotaxis of monocytes from control subjects but inhibited the chemotactic responsiveness of monocytes from atopic dermatitis patients. These findings suggest that an abnormal sensitivity of monocytes to histamine is an intrinsic feature of atopic dermatitis that may be detectable when the disease is quiescent. Furthermore, this abnormality may contribute to the impairment of monocyte chemotaxis that has been previously observed in patients with active atopic dermatitis.

Chemotaxis↗
PubMed1982

Structure-function relationship of [2Fe-2S] ferredoxins and design of a model molecule.

[2Fe-2S] ferredoxins isolated from various plants and algae comprise 93-99 amino acid residues and resemble each other not only in sequences, but also in physiological functions. One of them isolated from Spirulina platensis was subjected to X-ray analysis and its three dimensional structure is now known. [2Fe-2S] ferredoxins of a different type are found in halobacteria and comprise 128 amino acid residues. Both types of the [2Fe-2S] ferredoxins exhibit low redox potentials. By comparing the amino acid sequences of 28 [2Fe-2S] ferredoxins and the tertiary structure of S. platensis ferredoxin we predicted a common three-dimensional structure to the [2Fe-2S] ferredoxins and proposed a molecular surface area to be interacting with FNR. An artificial small molecule composed of 20 amino acid residues is designed on the basis of the tertiary structure of S. platensis ferredoxin. The amino acid sequence was predicted to be Pro-Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Thr-Cys-Ala-Gyl-Pro-Leu-Leu-Thr Cys-Val which should have a [2Fe-2S] cluster with a low redox potential.

Amino Acid Sequence↗
PubMed1982

Purification and amino acid sequence of a fern (Gleichenia japonica) ferredoxin.

A chloroplast-type ferredoxin was purified from a fern, Gleichenia japonica, and its amino acid sequence was determined. The conventional method for soft leaves proved to be unsuitable for the extraction of ferredoxin from G. japonica, but a good yield was obtained by blending the leaves in cold acetone. The analysis of 8 tryptic peptides of Cm-ferredoxin gave the complete amino acid sequence. The molecule consisted of a single polypeptide chain of 95 amino acid sequence. The molecule consisted of a single polypeptide chain of 95 amino acid residues and lacked tryptophan. Relatively high contents of phenylalanine and arginine were noted, some of which had unique locations in comparison with other ferredoxins. G. japonica ferredoxin did not show a close sequence homology with the ferredoxins from horsetails, which, like ferns, belong to Pteridophyta, or with those from plants of different taxonomical groups. The fern ferredoxins were suggested to form a unique group in the chloroplast-type ferredoxins.

Acetone↗
PubMed1982

Characterization of a ColE1-like plasmid isolated from Shigella sonnei.

A multicopy plasmid, 4.7 kb in size, was isolated from Shigella sonnei and named pKY1. This plasmid produces a colicin E1-like bacteriocin (colicin E1*) in E. coli cells. The cells harboring pKY1 are immune not only to this bacteriocin but also to colicin E1, and the cells harboring Co1E1 show immunity to colicin E1* as well. Although these two plasmid DNAs have different cleavage maps and are compatible with each other, pKY1 shows partial DNA homology with ColE1 DNA. In this paper, we report the isolation and properties of several Tn3 inserted pKY1 mutants, and propose a preliminary genetic map of pKY1. It was also found that this plasmid is not capable of self-transmission and is poorly mobilized by the F factor.

Chromosome Mapping↗
PubMed1982

Amino acid sequences of Nostoc strain MAC ferredoxins I and II.

The amino acid sequences of ferredoxins I and II from a blue-green alga, Nostoc strain MAC were determined. This alga is able to grow autotrophically in the light or heterotrophically in the dark. Analyses of tryptic peptides of Cm-proteins by conventional methods including solid-phase Edman degradation gave the complete amino acid sequences. Both molecules consisted of 98 amino acid residues and 34 amino acid differences including two deletions were found between the two. Comparing these sequences with those of ferredoxins from Chlorogloeopsis fritschii and Synechocystis 6714, which are also capable of growing under both conditions, showed that Nostoc strain MAC ferredoxin II had unique amino acids around the [2Fe-2S] cluster. This finding provides a structural basis for explaining the different chemical and functional properties of Nostoc strain MAC ferredoxin II reported in a previous paper (Hutson et al. (1978) Biochem. J. 172, 465-477).

Amino Acid Sequence↗
PubMed1982

Amino acid sequence of Synechocystis 6714 ferredoxin: a unique structural feature of unicellular blue-green algal ferredoxin.

The amino acid sequence of ferredoxin from Synechocystis 6714, a unicellular blue-green alga, was determined by a combination of conventional methods. The ferredoxin was composed of 96 amino acid residues and lacked methionine and tryptophan. The sequence was as follows: Ala-Ser-Tyr-Thr-Val-Lys-Leu-Ile-Thr- Pro-Asp-Gly-Glu-Asn-Ser-Ile-Glu-Cys-Ser-Asp-Asp-Thr-Tyr-Ile-Leu-Asp-Ala-Ala- Glu-Glu-Ala-Gly-Leu-Asp-Leu-Pro-Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Thr-Cys- Ala-Gly-Lys-Ile-Thr-Ala-Gly-Ser-Val-Asp-Gln-Ser-Asp-Gln-Ser-Phe-Leu-Asp-Asp- Asp-Gln-Ile-Glu-Ala-Gly-Tyr-Val-Leu-Thr-Cys-Val-Ala-Tyr-Pro-Thr-Ser-Asp-Cys-Thr-Ile-Glu-Thr-His-Lys-Glu-Glu-Asp-Leu-Tyr. In an alignment of various ferredoxins with high homology from unicellular and filamentous blue-green algae, Synechocystis 6714 ferredoxin showed 4 gaps. Those between residues 9 and 10 and between residues 12 and 13 were unique for the ferredoxins from the unicellular algae Synechocystis 6714 and Aphanothece sacrum (ferredoxin I). Therefore, ferredoxins from unicellular algae were distinguishable from those of filamentous algae in terms of the presence of gaps. This feature appears to coincide with the phylogenetic division between the two types of blue-green algae.

Amino Acid Sequence↗
PubMed1982

Amino acid sequence of Chlorogloeopsis fritschii ferredoxin: taxonomic and evolutionary aspects.

The amino acid sequence of Chlorogloeopsis fritschii ferredoxin was determined for its carboxymethylated derivative by using solid-phase sequencing, fragmentation with various enzymes, and manual Edman degradation procedures. The ferredoxin was composed of 98 amino acid residues and lacked methionine and tryptophan. The sequence was as follows: Ala-Thr-Tyr-Lys-Val-Thr-Leu-Ile-Asn-Asp-Ala-Glu- Gly-Leu-Asn-Gln-Thr-Ile-Glu-Val-Asp-Asp-Asp-Thr-Tyr-Ile-Leu-Asp-Ala-Ala-Glu- Glu-Ala-Gly-Leu-Asp-Leu-Pro-Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Thr-Cys-Ala-Gly-Lys-Ile-Lys-Ser-Gly-Thr-Val-Asp-Gln-Ser-Asp-Gln-Ser-Phe-Leu-Asp-Asp-Asp- Gln-Ile-Glu-Ala-Gly-Tyr-Val-Leu-Thr-Cys-Val-Ala-Tyr-Pro-Thr-Ser-Asp-Cys-Thr-Ile-Glu-Thr-His-Lys-Glu-Glu-Glu-Leu-Tyr. A phylogenetic tree was constructed on the basis of a comparison of various algal ferredoxins and it was found that C. fritschii ferredoxin was closely related to Mastigocladus laminosus ferredoxin, though they are in different genera of the blue-green algae. Aspects of the taxonomy and molecular evolution of blue-green algal ferredoxins are discussed.

Amino Acid Sequence↗
PubMed1982

Isolation and identification of a new growth inhibitor, raphanusanin, from radish seedlings and its role in light inhibition of hypocotyl growth.

A neutral growth inhibitor, for which the name raphanusanin is proposed, has been isolated in crystalline form from light-exposed Sakurajima radish (Raphanus sativus var. hortensis f. gigantissimus Makino) seedlings and identified as a new compound, 3-methoxy-4-methylthio-2-piperithione by spectrometric analyses.Applied raphanusanin inhibited the hypocotyl growth of etiolated radish and lettuce seedlings at concentrations higher than 1.5 x 10(-6) molar.The endogenous raphanusanin contents in cotyledons and hypocotyls of radish seedlings increased more under red light, but decreased or maintained the initial level in the dark. Its content in roots showed almost no change between the light and dark materials.

Journal Article↗
PubMed1981

Regulation of SOS functions: purification of E. coli LexA protein and determination of its specific site cleaved by the RecA protein.

The LexA protein of Escherichia coli was purified to more than 96% purity from cells harboring a recombinant plasmid carrying the lexA gene with the lacZ promoter sequence. The amino acid composition of the LexA protein and its amino-terminal sequence were analyzed. The results are in agreement with the prediction from the nucleotide sequence of the lexA gene. The LexA protein is cleaved into two polypeptides by E. coli RecA protein in the presence of ATP and single-stranded DNA. The site of the specific cleavage was determined by analyzing amino acid sequences of the cleaved products at the amino and carboxyl termini. The cleavage of the LexA protein by the RecA protein was found to occur at a single site between Ala84 and Gly85.

Bacterial Proteins↗
PubMed1981

Mutants of Shigella sonnei deficient in DNA polymerase I.

Mutants of Shigella sonnei (S. sonnei) deficient in DNA polymerase I were isolated after mutagenesis with nitrosoguanidine. The isolation of the mutants was facilitated by the use of a strain harboring plasmid pBR313 which required DNA polymerase I for its muliplication. The mutants isolated could not maintain the plasmid and became sensitive to methyl methanesulfonate (MMS) and to ultraviolet light (UV) irradiation. Assays performed on crude extracts established that the mutants were deficient in an enzyme with DNA polymerase activity. All of these properties are the same as those of E. coli polA. Several MMS-resistant revertants isolated from one of the S. sonnei polA mutants regained 3-120% of the DNA polymerase activity found in the extracts of the wild-type parent strain. Most though not all of the revertants could support the multiplication of plasmid pBR313.

DNA Polymerase I↗