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Biomedical subjects

Y Kanaoka

Publications and source records attributed to Y Kanaoka.

At least 19 recordsLinked to original sources
PubMed1994

Hac1: a novel yeast bZIP protein binding to the CRE motif is a multicopy suppressor for cdc10 mutant of Schizosaccharomyces pombe.

We cloned by phenotypic complementation a novel Saccharomyces cerevisiae's multicopy suppressor of the Schizosaccharomyces pombe cdc10-129 mutant which we call HAC1, an acronym of 'homologous to ATF/CREB 1'. It encodes a bZIP (basic-leucine zipper) protein of 230 amino acids with close homology to the mammalian ATF/CREB transcription factor and gel-retardation assays showed that it binds specifically to the CRE motif. HAC1 is not essential for viability. However, the hac1 disruptant becomes caffeine sensitive, which is suppressed by multicopy expression of the yeast PDE2 (Phosphodiesterase 2) gene. Although the mRNA level of HAC1 is almost constitutive throughout the cell cycle, it fluctuates during meiosis. The upstream region of the HAC1 gene contains a T4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. These results suggest that HAC1 may also be one of the meiotic genes.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1994

A novel biotinylated heterobifunctional cross-linking reagent bearing an aromatic diazirine.

The synthesis of a p-[(3-trifluoromethyl)diazirine-3-yl]benzoic acid derivative is described as a new carbene generating heterobifunctional cross-linking reagent. The cross-linker carries a biotin moiety in order to make use of avidin-biotin technology for specific manipulation of cross-linked components. To evaluate the ability of this reagent, the inter-subunit cross-linking of egg-white avidin tetramer was investigated. As a typical application of avidin-biotin technology for cross-linking experiments, a chemiluminescent detection method was examined to identify photobiotinylated components. A cross-linked dimeric product with an apparent molecular mass of 38 kDa was clearly visualized by the combined use of a horseradish peroxidase-streptavidin conjugate and a luminol-based chemiluminescent system.

Avidin↗
PubMed1994

[A case of metastatic lung tumor from acinic cell tumor of the parotid gland].

A 59-year-old man with metastatic lung tumor from acinic cell tumor of the parotid gland was reported. Five years after resection of the parotid tumor, the abnormal shadow on chest X-ray film was detected in the mass screening. The tumor was located in S10c of the right lung, and resected by partial lung resection. As pathological findings showed the same histology between the parotid gland and the lung, we diagnosed the metastatic lung tumor from acinic cell tumor of the parotid gland. Acinic cell tumor shall be slowly growing and occasionally developing the pulmonary metastasis. So, we have to carefully follow the patient in long-term periods.

Carcinoma, Acinar Cell↗
PubMed1994

[Partial resection of superior vena cava using two stage venous return catheter for a new application].

A case of invasive lung cancer was reported, in which operation partial resection and reconstruction of the invaded superior vena cava (SVC) was performed. During procedure in SVC, a two stage venous return catheter, which is ordinary used in cardiac operations, was used as a temporary SVC-right atrial internal bypass. This new application of the catheter was convenient and effective for resection and reconstruction of SVC.

Aged↗
PubMed1994

[A case of mediastinal emphysema due to blunt trauma that a continuous drainage to the extrapleural space took effect].

A 70-year-old male was admitted to our hospital with chest bruise, resulting in fracture of the right rib. Nine hours later, the patient came to use again with a chief complaint of dyspnea and chest oppression. He had extensive subcutaneous emphysema in the upper half of the body. Chest X-ray films revealed remarkable mediastinal emphysema and collapse in a part of right lung. Chest CT scan disclosed enlargement of extrapleural cavity. These findings suggested progression of mediastinal emphysema. Continuous drainage to the extrapleural cavity was performed and the clinical course was uneventful. Thus, a satisfactory result can be obtained by extrapleural drainage in a patient with severe mediastinal emphysema.

Aged↗
PubMed1994

[A case of chronic traumatic dissecting aneurysm of the thoracic aorta].

A case of chronic traumatic dissecting aneurysm was reported. A 61-year-old man was admitted to our hospital for multiple trauma caused in traffic accident. MRI, performed for evaluation of the spinal injury, revealed dissection of the thoracic descending aorta by chance, seven months after injury. Retrospectively CT, just after admission, showed bleeding around the thoracic descending aorta. Replacement of thoracic aorta was performed after 33 months from the traffic accident, for enlargement of dissecting lumen accompanied with hoarseness. The postoperative course was uneventful and the patient returned to his daily life successfully.

Aortic Dissection↗
PubMed1992

A site-directed antibody that inhibits phosphorylation of the rat-brain sodium channel by cyclic-AMP-dependent protein kinase.

Antibodies were raised against three peptides corresponding to the potential protein phosphorylation sites of rat-brain sodium channels by the cAMP-dependent protein kinase (PKA). One of the antibody against sequence (C561-575) reacted to the channel molecule. This immunoreaction occurred in a sequence-specific manner, as it was inhibited by the antigen peptide itself but not inhibited by two other peptides. Although PKA phosphorylates two synthetic peptides, C561-575 and C681-689, of the three, anti-(C561-575) antibody can only inhibit the phosphorylation of peptide (C561-575). PKA catalyzed the incorporation of 3.1-3.5 mol of phosphates into the alpha subunit of the purified sodium channel. The anti-(C561-575) antibody inhibited the channel phosphorylation by 40%. Digestion of the phosphorylated sodium channel with lysyl endoproteinase yielded four major phosphorylated fragments of 3.5, 5.0, 7.0, and 10 kDa. However, similar digestion of the channel that was phosphorylated in the presence of anti-(C561-575) antibody did not yield the phosphorylated fragment of 3.5 kDa and gave the 7.0 kDa fragment in reducing yield. Inspection of these phosphorylated fragments by the predicted sizes of the peptide fragments containing the five potential phosphorylation sites gives a conclusion that anti-(C561-575) antibody inhibits the phosphorylation on Ser-573 completely, and on either Ser-610 or Ser-623 partially, probably due to their proximity orientation in the tertiary structure.

Amino Acid Sequence↗
PubMed1992

Photolabeled sites with a tetrodotoxin derivative in the domain III and IV of the electroplax sodium channel.

Forty three percent of the labeled sites, at least, in the electroplax sodium channel with a photoactivable tetrodotoxin derivative were identified by probing protease-digested labeled fragments with several sequence-directed antibodies. They are located in the loop between segments S5 and S6 of domain IV, as well as the region containing transmembrane segment S6 and adjacent extracellular and cytoplasmic sequences in domain III. No photolabeled fragments were detected in the corresponding region of domain I. These results suggest that C-11 of tetrodotoxin where the photoreactive moiety is attached orients to the region between S5 and S6 in domain III and IV. Probable orientation of the tetrodotoxin molecule in sodium channels is considered by taking together with the recent report of the site-directed mutagenesis.

Amino Acid Sequence↗
PubMed1992

Anhydrosubtilisin-catalyzed peptide synthesis.

Anhydrosubtilisin was found to be a good catalyst for the peptide synthesis though its hydrolytic activity was fully inhibited. Amino acid (peptide) p-chlorophenyl ester (acyl donor) was coupled with amino acid (peptide) amide in the presence of the modified enzyme. The method did not afford by-products resulting from the hydrolysis of the acyl donor. This is the most advantageous characteristic of the method, since the hydrolysis of the acyl donor is unavoidable for the methods using catalytically active proteases. Anhydrosubtilisin was further shown to be useful for the fragment condensation of peptides.

Amidohydrolases↗
PubMed1992

Structural characterization of the dihydropyridine receptor-linked calcium channel from porcine heart.

Ca(2+)-channel was purified 230-fold from digitonin extracts of the porcine cardiac sarcolemmal membranes by means of a four-step procedure. Two antibodies, a site-directed antibody against the sequence 1691-1707 of the rabbit cardiac alpha 1 subunit (anti-CCP5) and a monoclonal antibody directed to rabbit skeletal muscle alpha 2 delta subunit-complex (MCC-1), effectively immunoprecipitated the 125I-labeled cardiac Ca(2+)-channel complex in 0.2% digitonin. SDS-PAGE analysis of the immunoprecipitates under reducing conditions revealed that the cardiac channel is mainly composed of two large polypeptides of 190 and 150 kDa, and five smaller polypeptides of 60, 55, 35, 30, and 25 kDa. An additional polypeptide of either 79 or 55 kDa is crosslinked with the 190 kDa component to form 250-270 kDa (approximately 270 kDa) to the extent of 15-20% through disulfide bond(s). The 190 kDa component (alpha 1) is responsible for photoaffinity labeling with [3H]diazepine, since minor photolabeled approximately 270 kDa was converged to the major labeled 190 kDa component when electrophoresed under reducing conditions. The 150 kDa component (alpha 2) was derived by reduction of disulfide bonds from another 190 kDa component of glycopolypeptide which was separated from the channel complex in 1% Triton X-100 and capable of binding to WGA-Sepharose. The four smaller components of 60, 35, 30, and 25 kDa were not covalently associated with the large components through disulfide bonds, whereas the 55 kDa polypeptide was suggested to be a mixture of two kinds of peptides with respect to the disulfide bond: one was crosslinked with alpha 1 through disulfide linkage and the other was not covalently associated with any other component.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Characterization of saccharide moiety in the electroplax sodium channel.

Carbohydrate chains on the large peptide of the voltage-sensitive sodium channel from Electrophorus electricus electroplax have been partially characterized by the lectin-blotting technique combined with digestion using three glucosidases: neuraminidase, endo-beta-N-acetylglucosaminidase H, and peptide: N-glycosidase F. The results show that both N-linked oligosaccharides and O-linked (mucin-type) oligosaccharides are present. In N-linked oligosaccharides, the results suggest the presence of complex- and hybrid-type oligosaccharides which contain bisecting N-acetylglucosamine(s), as well as the complex-type oligosaccharides with the alpha-Fuc-GlcNAc-(Asn) residue(s). In O-linked oligosaccharides, they must carry Gal beta1----3GalNAc- moieties which contain NeuNAc residues in the terminal.

Animals↗
PubMed1991

Identification of 1,4-dihydropyridine binding regions within the alpha 1 subunit of skeletal muscle Ca2+ channels by photoaffinity labeling with diazipine.

To identify regions that are involved in the formation of the dihydropyridine receptor site of skeletal muscle L-type Ca2+ channels, the alpha 1 subunit of the channel complex was specifically labeled with the 1,4-dihydropyridine-receptor-selective photoaffinity probe [3H]diazipine. Photoaffinity-labeled regions were identified by probing labeled proteolytic fragments with several anti-peptide antibodies recognizing different segments of the alpha 1 sequence. Forty to 50% of the alpha 1-associated [3H]diazipine label was contained in the tryptic fragment between Arg-988 and Ala-1023 derived from the loop between segments S5 and S6 in domain III. This region corresponds to a portion of the channel that is believed to contribute to formation of the transmembrane pore. Twenty to 30% of the labeling occurred in a V8 protease fragment between Glu-1349 and Trp-1391. This fragment contains transmembrane segment S6 of domain IV and has previously been shown to form part of the drug receptor for phenylalkylamine Ca2+ antagonists. Our data suggest that the dihydropyridine receptor is formed by close apposition of two discontinuous regions of the alpha 1 subunit sequence in domains III and IV. In light of previous work localizing this receptor site to the extracellular surface of the lipid bilayer, it is proposed that amino acid residues at the extracellular surface in the loop connecting segments IIIS5 and IIIS6 and at the extracellular end of segment IVS6 contribute to formation of the dihydropyridine receptor site.

Affinity Labels↗
PubMed1991

A new hereditary abnormal protein C (protein C Yonago) with a dysfunctional Gla-domain.

A familial abnormal protein C most probably with the dysfunctional Gla domain was found in a 60-year-old man with recurrent thrombosis. Namely, the anticoagulant activity as measured by the APTT method and the antigen level by an ELISA utilizing a calcium-dependent antibody were reduced to nearly half of normal, 43.5% and 2.1 micrograms/ml (normal range: 2.8-5.0 micrograms/ml), respectively. On the other hand, the amidolytic activity determined on a synthetic chromogenic substrate, S-2366, and the total antigen measured by an ELISA utilizing a polyclonal antibody were both in the normal range, 74.1% and 83% of normal, respectively. Crossed immunoelectrophoresis showed more anodal migration than the normal control in the presence of calcium ions, and adsorption of protein C to barium citrate was insufficient. These data altogether indicated that a half population of protein C in the patient's plasma was dysfunctional in the Gla domain or its related structures. Four other members of his immediate family were found to have the same abnormality of protein C, although they had been all asymptomatic. We thus conclude that the dysfunctional protein C is hereditary, and that the abnormalities noted in several tests are most likely due to a structural defect residing in the Gla or its related regions. We hereby designate this abnormal protein C as protein C Yonago.

Blood Coagulation Tests↗
PubMed1991

Diazipine, a novel photoaffinity probe for dihydropyridine receptors of calcium channels.

A new 1,4-dihydropyridine photoaffinity ligand, [3H]diazipine, has been assessed by binding and photolabeling, and compared with a currently used [3H]azidopine. [3H]Diazipine reversibly binds to skeletal muscle Ca2+ channels with a similar affinity to [3H]azidopine, but [3H]diazipine labels the channel two times more efficiently and no release of the incorported amount is observed after dithiothreitol treatment.

Affinity Labels↗
PubMed1991

Application of bimane-peptide substrates to spectrofluorometric assays of metalloendopeptidases.

A spectrofluorometric method for sensitive determination of metalloendopeptidase activity has been developed by using a bimane-peptide containing a tryptophan residue, i.e. 1,7-dioxo-2,5,6-trimethyl-1H,7H-pyrazolo[1,2-alpha]pyrazol-3-yl-methyl- thiomethylcarbonyl-phenylalanyl-tryptophanyl-leucine (Bim-SCH2CO-Phe-Trp-Leu-OH). Such an "intramolecularly quenched" substrate was originally designed for a sensitive assay of angiotensin I converting enzyme (ACE) [Sato, E. et al. (1989) Chem. Pharm. Bull. 37, 145-147]. All the typical metalloendopeptidases tested, such as thermolysin, Pseudomonas aeruginosa (Ps.) elastase, Streptomyces griseus metalloendopeptidases I and II (SGMPI and SGMPII), and alkinonase A, a metalloendopeptidase from Streptomyces violaceorectus, cleaved this substrate strictly at a Phe-Trp bond, leading to a marked increase in fluorescence. Kinetic parameters of the enzymatic hydrolyses of five kinds of analogous bimane substrates were compared to examine how the nature of neighboring amino acid residues on either side of the cleavable bond affects the catalytic efficiency of each of the metalloendopeptidases. Bim-SCH2CO-Phe-Trp-Leu-OH was most efficiently hydrolyzed by all of these enzymes. The use of this substrate made it possible to determine minute amounts of metalloendopeptidases, especially those originating from Streptomycetes (for example, as little as 10 fmol of SGMPII).

Amino Acid Sequence↗
PubMed1991

Fluorogenic bimane substrates with dabsyl group for endopeptidases; chymotrypsin, collagenase and thermolysin.

It was found that the fluorescence of 9,10-dioxa-syn-3,4,6,7-tetramethylbimane (bimane) can be quenched in the presence of dimethylaminoazobenzensulfonyl (Dabsyl) group. New combination of bimane (fluorophor) and dabsyl group (quencher) was applied to the syntheses of intramolecularly quenched fluorogenic substrates for hydrolytic enzymes. Bimane peptides containing dabsyl group were prepared, and were shown to be useful fluorogenic substrates for the assay of endopeptidases such as chymotrypsin, collagenase and thermolysin.

Bridged Bicyclo Compounds↗