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Biomedical subjects

H Matsubara

Publications and source records attributed to H Matsubara.

At least 343 records · Page 19Linked to original sources
PubMed1986

A retrospective evaluation of the medical treatment of malignancy-associated hypercalcemia.

Little is known about the relative effectiveness and potency of a variety of treatments for malignancy-associated hypercalcemia, or how beneficial the reversal of hypercalcemia is to these patients. Therefore, 146 trials of treatment for hypercalcemia between 1980 and 1983 at the National Cancer Center Hospital, Tokyo, were evaluated retrospectively. Serum calcium levels exhibited the largest decrease in the mithramycin-treated group (decrease; 5.4 +/- 1.8 mg/dl, mean +/- SD, n = 22), followed by the groups given calcitonin plus glucocorticoids (3.1 +/- 2.3, n = 11), glucocorticoids (2.3 +/- 2.3, n = 18), calcitonin (1.8 +/- 1.6, n = 51), hydration (1.3 +/- 2.5, n = 27), and indomethacin (1.0 +/- 2.3, n = 17). The effective rate was the highest with mithramycin (100%) and then with calcitonin plus glucocorticoids (73%) and with glucocorticoids (61%); it was less than 50% in the other modalities of treatment. In patients with pretreatment serum calcium levels of 14 mg/dl or more, the survival rate improved significantly in those whose serum calcium levels decreased below 12 mg/dl compared with those whose serum calcium remained above 12 mg/dl (50% survival; 35 vs. 9 days, P less than 0.01). These data provide a good guideline and a rationale in choosing the modality of treatment. In addition, the data show that the gain in the survival time achieved by successful treatment of hypercalcemia is clinically significant, because it is long enough to conduct additional antitumor therapy.

Adult↗
PubMed1985

Preliminary X-ray diffraction studies on a ferredoxin from the thermophilic archaebacterium, Thermoplasma acidophilum.

A ferredoxin from the thermophilic archaebacterium, Thermoplasma acidophilum, is supposed to contain two (4Fe-4S) active centers; one center could be linked by four cysteine residues to the protein and the other bonded with three cysteines and an unknown group. This ferredoxin has been crystallized by salting-out against 2.3 M-ammonium sulfate solution. The space group is P21212 with cell dimensions of a = 59.20 A, b = 52.77 A and c = 41.28 A. Four molecules pack in the unit cell with Vm = 2.03 A3/dalton.

Amino Acid Sequence↗
PubMed1985

Analysis of receptor-binding site in Escherichia coli enterotoxin.

Heat-labile enterotoxin produced by enterotoxigenic Escherichia coli and cholera enterotoxin are both composed of A and B subunits. The A subunit is an enzymatically active ADP-ribosylating subunit, while the B subunit, consisting of 103 amino acids, binds the toxin to a receptor, GM1-ganglioside, on the cell surface. A mutant isolated after treatment of E. coli producing heat-labile enterotoxin with N-methyl-N'-nitro-N-nitrosoguanidine produces a B subunit that is unable to bind to ganglioside. This subunit was purified and its primary amino acid sequence was determined. It differed from the native B subunit in only one amino acid at position 33; namely it had aspartate instead of glycine at position 33 from the N terminus. Thus glycine at position 33 from the N terminus of the B subunit is important for binding the B subunit to the ganglioside receptor.

Adenosine Diphosphate Ribose↗
PubMed1985

Glycosphingolipids of leukemic cells in adult T-cell leukemia-lymphoma.

We analyzed lipids from leukemic cells of two patients with adult T-cell leukemia and compared them with those from T-cell lymphocytes of normal subjects. The neutral glycosphingolipids and gangliosides which were isolated were characterized by thin-layer chromatography and neuraminidase treatment. Both leukemic cells and normal lymphocytes had monoglycosylceramide and diglycosylceramide as major neutral glycosphingolipids. In one patient, diglycosylceramide was markedly increased. II3NeuAc-LacCer (GM3) and more complex gangliosides were detected in both cells. The most characteristic finding in leukemic cells was the occurrence of a disialylated ganglioside, II3(NeuAc)2-LacCer (GD3), which is not found in normal lymphocytes and neutrophils. This ganglioside may be due to the induced synthesis in association with malignant transformation.

Cell Membrane↗
PubMed1985

Complete amino acid sequence of an alpha-amylase inhibitor in wheat kernel (0.19-inhibitor).

Amino acid composition of the 0.19-inhibitor from wheat kernel is very similar to that of the 0.53-inhibitor, but a marked difference in inhibitory activity towards human salivary and pancreatic alpha-amylases was detected between the two inhibitors. Elucidation of the primary structure of the 0.19-inhibitor and structural comparison with the 0.53-inhibitor is essential to understand not only the mechanism of the selective inhibitory behaviors but also evolutional relationship of these inhibitors. The complete amino acid sequence of the 0.19-inhibitor was determined after cleaving the protein with cyanogen bromide and trypsin. As in the case for the 0.53-inhibitor, the 0.19-inhibitor is composed of two identical subunits with 124 amino acid residues. Comparison of the sequence of the 0.53- and 0.19-inhibitor shows very high sequence homology with amino acid substitutions at seven positions.

Amino Acid Sequence↗
PubMed1985

Complete amino acid sequence of the ubiquinone binding protein (QP-C), a protein similar to the 14,000-dalton subunit of the yeast ubiquinol-cytochrome c reductase complex.

The amino acid sequence of the ubiquinone binding protein (QP-C) in the cytochrome bc1 region of the mitochondrial electron transfer chain was determined by analysis of peptides obtained by cyanogen bromide cleavage and staphylococcal protease digestion of succinylated derivatives. It was found to consist of 110 amino acid residues and its amino terminus to be blocked by an acetyl group, as determined by mass spectrometry of the amino-terminal peptide and a comparison with peptides chemically synthesized on high-performance liquid chromatography. The molecular weight of this ubiquinone binding protein including the acetyl group was calculated to be 13,389. The predicted secondary structure of QP-C has alpha-helical content of about 50% and QP-C was classified as an "all-alpha" or "alpha + beta" protein. This is the first report describing the amino acid sequence of the ubiquinone binding protein. A comparison of this sequence with that of the 14-kDa subunit of the yeast ubiquinol-cytochrome c reductase complex from the nucleotide sequence showed these two sequences to be quite similar.

Amino Acid Sequence↗
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↗
PubMed1985

Amino acid sequence of a ferredoxin from thermoacidophilic archaebacterium, Sulfolobus acidocaldarius. Presence of an N6-monomethyllysine and phyletic consideration of archaebacteria.

The amino acid sequence of a ferredoxin from a thermoacidophilic archaebacterium, Sulfolobus acidocaldarius, was determined by a combination of various conventional methods to be as follows: Gly-Ile-Asp-Pro-Tyr-Arg-Thr-His-Lys-Pro-Val-Val-Gly-Asp-Ser-Ser-Gly-His- Lys-Ile -Tyr-Gly-Pro-Val-Glu-Ser-Pro-Lys(Me)-Val-Leu-Gly-Val-His-Gly-Thr-Ile-Val -Gly-Va l-Asp-Phe-Asp-Leu-Cys-Ile-Ala-Asp-Gly-Ser-Cys-Ile-Thr-Ala-Cys-Pro-Val-As n-Val-P he-Gln-Trp-Tyr-Glu-Thr-Pro-Gly-His-Pro-Ala-Ser-Glu-Lys-Lys-Ala-Asp-Pro-V al-Asn- Glu-Gln-Ala-Cys-Ile-Phe-Cys-Met-Ala-Cys-Val-Asn-Val-Cys-Pro-Val-Ala-Ala- Ile-Asp -Val-Lys-Pro-Pro. It was composed of 103 amino acid residues giving a molecular weight of 10,908 excluding Fe and S atoms. This ferredoxin contained an N6-monomethyllysine residue at position 29 which was determined by a comparison of the elution profile of the acid hydrolysates of the protein and peptides on an amino acid analyzer with three methyl derivatives of lysine and also by field desorption mass spectrometry of a purified peptide. The ferredoxin has only 7 cysteine residues, which probably participate in constructing the Fe-S clusters of this ferredoxin, indicating the presence of a unique chelate structure. Comparison of this ferredoxin with other archaebacterial ferredoxins indicated that the archaebacteria might have multiple origins in an evolutionary tree.

Amino Acid Sequence↗
PubMed1985

Complete amino acid sequence of cytochrome c from the honeybee, Apis mellifera, and evolutionary relationship of the honeybee to other insects on the basis of the amino acid sequence.

The complete amino acid sequence of cytochrome c purified from the honeybee, Apis mellifera was determined. Only one molecular species of cytochrome c was found in the honeybee throughout its metamorphic stages. On the basis of a comparison of the amino acid sequence of honeybee cytochrome c with those of cytochromes c from other insects, it seems that the bee has evolutionarily appeared earlier than would be expected from the morphological and fossil evidence. If the classical phylogenetic relationships of the honeybee are correct, the evolutionary rate of cytochrome c must have been more rapid in the honeybee than in other insects.

Amino Acid Sequence↗
PubMed1985

Ferredoxin from a liverwort, Marchantia polymorpha. Purification and amino acid sequence.

Marchantia polymorpha ferredoxin was purified by DE-52 and Sephadex G-75 column chromatographies to homogeneity. The complete amino acid sequence of the carboxymethylated (Cm) ferredoxin was determined by conventional methods to be as follows. Thr-Phe-Lys- Val-Thr-Leu-Asn-Thr-Pro-Thr-Gly-Gln-Ser-Val-Ile-Asp-Val-Glu-Asp- Asp-Glu-Tyr-Ile-Leu-Asp-Ala-Ala-Glu-Glu-Ala-Gly-Leu-Ser-Leu-Pro- Tyr-Ser-Cys-Arg-Ala-Gly-Ala-Cys-Ser-Ser-Cys-Ala-Gly-Lys-Val-Thr- Ala-Gly-Glu-Val-Asp-Gln-Ser-Asp-Glu-Ser-Phe-Leu-Asp-Asp-Asp-Gln- Met-Asp-Glu-Gly-Tyr-Val-Leu-Thr-Cys-Ile-Ala-Tyr-Pro-Thr-Ser-Asp- Leu-Thr-Ile-Asp-Thr-His-Gln-Glu-Glu-Ala-Leu-Ile. The total number of amino acid residues was 95 and the molecular weight was calculated to be 10,174, excluding iron and sulfur atoms. The distribution of the four cysteine residues chelating the two iron atoms was identical to those of other [2Fe-2S] ferredoxins. The relationship between M. polymorpha and other plants was discussed in terms of plant phylogeny.

Amino Acid Sequence↗
PubMed1985

The sulfhydryl groups of ferredoxin-NADP+ oxidoreductases: is a disulfide bond really present?

The sulfhydryl groups of three ferredoxin-NADP+ oxidoreductases [EC 1.18.1.2] (FNR) two from blue-green algae, Spirulina sp. and Synechococcus sp., respectively, and one from spinach, were analyzed by carboxymethylation and titration with sulfhydryl reagents under different conditions. Five sulfhydryl groups in Spirulina and spinach enzymes and four in Synechococcus enzyme were found to be in reduced forms. There was no disulfide bond in any FNR tested. The results in the present experiment contradict those reported by Karplus et al. [Biochemistry 23, 6576-6583 (1984)].

Amino Acids↗