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Y Kamio

Publications and source records attributed to Y Kamio.

At least 145 records · Page 8Linked to original sources
PubMed1991

Nucleotide sequence of pnl gene from Erwinia carotovora Er.

The nucleotide sequence of pnl gene encoding pectin lyase (PNL; EC4.2.2.10)from Erwinia carotovora Er was determined. The structural gene of pnl consisted of 942 base pairs. An open reading frame that could encode a 33,700 dalton polypeptide consisting 314 amino acids was assigned. The molecular size of the polypeptide predicted from the amino acid composition was close to the value of PNL determined in E.carotovora Er. The nucleotide sequence of the 5'-flanking region showed the presence of the consensus sequence of ribosome binding site, Pribnow box and the RNA polymerase recognition site in E.carotovora and Escherichia coli. Between the presumed Pribnow box and the ribosome binding site, two pairs of inverted repeats were found. By comparing the predicted amino acid sequences of pnl, several reported bacterial pectate lyases and Aspergillus niger pectin lyase, short regions of homology were found despite the different substrate specificities of these enzymes.

Amino Acid Sequence↗
PubMed1991

Purification and Properties of beta-1, 4-Xylanase from Aeromonas caviae W-61.

Aeromonas caviae W-61, which was isolated from water samples at the Faculty of Agriculture, Tohoku University, produced beta-1, 4-xylanase (1,4-beta-d-xylan xylanohydrolase; EC 3.2.1.8) extracellularly. The xylanase was purified to homogeneity by using DEAE-Sephadex A-50, CM-Sephadex C-50, and Sephadex G-100 column chromatographies. The molecular weight of the purified enzyme was estimated to be 22,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of the enzyme was 9.2. The optimal pH and temperature for the activity of the enzyme were 7.0 and 55 degrees C, respectively. The enzyme was stable at pH 7.0 at temperatures of up to 50 degrees C. As enzymatic products, various xylo-oligosaccharides such as xylobiose, xylotriose, xylotetraose, and xylopentaose were formed, and only a small amount of xylose was detected. The purified enzyme did not hydrolyze starch, cellulose, carboxymethylcellulose, or beta-1, 3-xylan.

Journal Article↗
PubMed1991

Purification and properties of two membrane alkaline phosphatases from Bacillus subtilis 168.

Two alkaline phosphatases were extracted from the membranes of Bacillus subtilis 168 stationary-phase cells and purified as homogeneous proteins by hydroxyapatite column chromatography. Alkaline phosphatases I and II differed in several properties such as subunit molecular weight, substrate specificity, thermostability, Km, pH stability, and peptide maps.

Alkaline Phosphatase↗
PubMed1991

Cloning and characterization of the pectate lyase III gene of Erwinia carotovora Er.

A pectate lyase gene III (pel III) of Erwinia carotovora Er was cloned. The gene was expressed independently of a vector promoter in both E. carotovora Er and Escherichia coli. The pel III product was largely excreted in the culture medium of E. carotovora Er, while the product was only exported to the periplasmic space and was not excreted in the medium of E. coli. Nucleotide sequence analysis of pel III disclosed an open reading frame of 1,122 bp encoding a protein of 374 amino acids. The deduced amino acid sequence contained the N-terminal 30 amino acid sequence from the purified pectate lyase III (PL III) indicating the presence of a 22-amino-acid signal peptide. A putative ribosome-binding site was found to be 9 bp upstream of the start codon. The location of pel III was about 5.6 kb downstream of pel I. The PL III showed 80% homology in the amino acid sequence with the PL I of E. carotovora Er.

Amino Acid Sequence↗
PubMed1990

Cloning and expression of pectin lyase gene from Erwinia carotovora in Escherichia coli.

A pectin lyase (PNL; EC 4.2.2.10) gene of Erwinia carotovora Er was cloned and expressed in Escherichia coli. The analysis of the nucleotide sequence of the 0.6 kb StuI-EcoRI fragment, which was hybridized with the mixed oligonucleotide probe for PNL gene, revealed the presence of an open reading frame (0RF) and correlated exactly with the known N-terminal 18 amino acid sequence of PNL. When a plasmid pTN2159, which has a BamHI-EcoRI fragment containing this ORF, was introduced into E. coli JM109, PNL was not expressed. When a tac-promoter was inserted in front of the ORF, PNL was efficiently expressed in E. coli. Synthesis of PNL by E. coli was also confirmed by immunoblot analysis.

Amino Acid Sequence↗
PubMed1990

Effects of mutations in the repA gene of plasmid Rts1 on plasmid replication and autorepressor function.

We constructed a system in which wild-type RepA or RepAcop1 protein was supplied in trans in various amounts to coexisting mini-Rts1 plasmids by clones of the repA or repAcop1 gene under the control of the native promoter with or without its operator sequence. RepAcop1 protein which contains a single amino acid substitution (Arg-142 to Lys) within its 288 amino acids could initiate the replication of the mini-Rts1 plasmid efficiently at both 37 and 42 degrees C even if it was supplied in excess. In contrast, excess wild-type RepA inhibited plasmid replication at 37 degrees C but supported replication at 42 degrees C. Therefore, it appears that the initiator activity of RepA is not related to the incompatibility phenotype associated with an excess of RepA protein. An immunoblot analysis revealed that neither RepA nor RepAcop1 synthesis was temperature sensitive and that both were autogenously regulated to a similar extent because of the presence of an operator located immediately upstream of the promoter. Two mutant RepA proteins, each of which contains a 4-amino-acid insertion in the middle of the protein, maintained the autorepressor and incompatibility activities but lost the ori(Rts1)-activating function.

Ampicillin Resistance↗
PubMed1990

[Potentiating effect of spirometric maneuver on bronchial responsiveness to methacholine in asthmatic subjects--the role of deep inspiration and forced expiration].

We previously reported that spirometric maneuver (SM) had potentiating effect on bronchial responsiveness (BR) in asthmatic subjects but not in normal subjects. SM consists of deep inspiration to TLC (DI) and forced expiration to RV (FE). In this study, we examined the effect of SM, DI and FE on BR in 9 asthmatic subjects. Provocative concentration of methacholine producing a 35% fall in respiratory conductance (PC35-Grs) was significantly (p less than 0.02 and p less than 0.025) decreased from 0.34 mg/ml (GSEM, 1.51) to 0.16 mg/ml (GSEM, 1.45) and 0.14 mg/ml (GSEM, 1.51) by SM and DI, respectively but it was not altered by FE. These findings indicate that potentiating effect of SM on BR which is characteristic of asthma may be due to DI effect.

Adult↗
PubMed1990

[Thromboxane A2 could be involved in bronchial hyperresponsiveness to methacholine in asthmatic subjects but not in bronchitic subjects].

To determine whether the involvement of thromboxane A2 in bronchial hyperresponsiveness is specific to asthma, we examined the effects of a selective thromboxane synthetase inhibitor (OKY-046) and a cyclooxygenase inhibitor (indomethacin) on bronchial responsiveness to methacholine in patients with bronchial asthma and chronic bronchitis. The provocative concentration of methacholine producing a 20% fall in forced expiratory volume in one second (PC20-FEV1) was measured before and after oral administration of OKY-046 and indomethacin in eight asthmatic and 10 bronchitic subjects. Baseline FEV1 value was not altered by OKY-046 or indomethacin. The geometric mean value of PC20-FEV1 increased significantly (p less than 0.005) from 1.78 to 4.27 mg/ml after OKY-046 in asthmatic subjects, but not in bronchitic subjects. On the other hand, PC20-FEV1 was not altered by indomethacin in all subjects. It was concluded that the involvement of thromboxane A2 in bronchial hyperresponsiveness may be specific to asthma.

Asthma↗
PubMed1990

[Relationship between cough threshold to inhaled tartaric acid and sex, smoking and atopy in humans].

It has been reported that angiotensin converting enzyme inhibitor (ACE-I) elicits dry cough more frequently in women than in men. This study was designed to evaluate whether airway cough receptors are more sensitive in women than in men. Cough threshold to inhaled tartaric acid was measured in 33 men and 29 women. In non-atopic and non-smoking subjects, geometric mean value of cough threshold in women was 10.0 (GSEM, 1.29) %, which was significantly (p less than 0.02) lower than that in men, 22.5 (GSEM, 1.30) %. In non-atopic men, the cough threshold was significantly (p less than 0.05) lower in smokers (9.3 (GSEM, 1.57) %) than in non-smokers. In non-smoking women, the cough threshold was significantly (p less than 0.02) lower in atopic subjects (4.2 (GSEM, 1.33) %) than in non-atopic subjects. These results demonstrated that airway cough receptors may be more sensitive in women, smoking men and atopic women.

Administration, Inhalation↗
PubMed1990

[Effect of deep inspiration on maximum expiratory flow (Vmax) depends on basal bronchomotor tone in young healthy females].

The relationship between the effect of deep inspiration on Vmax and basal bronchomotor tone was studied by partial and maximum expiratory flow-volume curve in 16 young healthy females (20-21 years old). Effect of deep inspiration on Vmax (DI index; (PEF25-MEF25)/PEF25) significantly related to percent increase in PEF25 not only by inhalation of ipratropium bromide (r = 0.81, p less than 0.0002) but also by inhalation of salbutamol (r = -0.62, p less than 0.01). Furthermore, day to day variation of DI index significantly related to day to day variation of PEF25 (r = 0.68, p less than 0.005) but not to that of MEF25. These findings suggest that the bronchodilating effect of deep inspiration in young healthy females may depend on intensity of basal bronchomotor tone caused by tonic vagal nerve activity.

Adult↗
PubMed1989

Purification and characterization of cytotoxin from the crude extract of Pseudomonas aeruginosa.

Pseudomonas aeruginosa cytotoxin is a protein toxin exhibiting cytotoxic effects on various eukaryotic cells. The toxin was purified from a crude extract of Pseudomonas aeruginosa 158 by trypsin treatment and serial chromatography. The purified cytotoxin was electrophoresed as a single protein band on polyacrylamide gel electrophoresis (PAGE) in the presence or absence of sodium dodecyl sulfate (SDS). The molecular weight of the purified toxin was determined to be 29,000 by SDS-PAGE and gel filtration chromatography in the presence of 6 M guanidine hydrochloride; the isoelectoric point was pH 6.0. The N-terminal amino acid sequence of the purified toxin was determined. The purified toxin showed the strongest cytotoxic effect on rabbit polymorphonuclear leukocytes and diverse degrees of cytotoxic effects on various eukaryotic cells including red blood cells and cultured cells.

Amino Acid Sequence↗
PubMed1989

Enhancement of both intracellular uptake and antitumor action of cisplatinum on human neuroblastoma cells by encapsulation in liposomes.

Phospholipid vesicles (phosphatidylcholine:phosphatidylserine:cholesterol = 6:2:3 in molar ratio) with a small unilamellar structure were used as drug carriers for introducing cis-diamminedichloroplatinum (CDDP) into human neuroblastoma cells, IMR-32, GOTO, Nagai, and TGW. DNA synthesis of IMR-32 cells among the human neuroblastoma cell lines was inhibited most strongly by CDDP-liposomes. CDDP-liposomes dose-dependently inhibited the DNA synthesis of IMR-32 in a similar fashion to that observed with free CDDP, but the drug concentration required to induce 50% inhibition of DNA synthesis for CDDP-liposomes (IC50: 0.7 micrograms CDDP/ml) was 1/3 of the IC50 for free CDDP (2.0 micrograms CDDP/ml). In support of the marked growth-inhibitory action of CDDP-liposomes, the intracellular incorporation rate of CDDP-liposomes was 3-fold higher when liposomes were used as carriers than when free CDDP was directly applied. CDDP-liposomes showed a stronger growth inhibition on IMR-32 cells at a high cell density than at a low density in culture. CDDP-liposomes were rapidly incorporated by IMR-32 cells within 5 min, resulting in the inhibition of DNA synthesis to 40% of the control. Swiss albino mouse 3T3 cells were less inhibited by CDDP-liposomes than by free CDDP, suggesting that encapsulation of CDDP in liposomes decreases cytotoxicity to normal cells.

Biological Transport↗
PubMed1989

Pseudomonas aeruginosa cytotoxin: the nucleotide sequence of the gene and the mechanism of activation of the protoxin.

The gene encoding cytotoxin (ctx) was cloned from Pseudomonas aeruginosa 158 and the nucleotide sequence was determined. The structural gene of ctx encodes the procytotoxin of 286 amino acid residues with a molecular mass of 31,681 Daltons. Procytotoxin was activated by removal of 20 amino acid residues from the C terminus with trypsin. The cloned ctx gene was not expressed in either an Escherichia coli strain or a cytotoxin non-producing strain of P. aeruginosa. An expression system for the ctx gene was constructed by placing the structural gene of ctx downstream of tac promoter on a broad host-range vector plasmid.

Amino Acid Sequence↗
PubMed1988

Nucleotide sequence and copy control function of the extension of the incI region (incI-b) of Rts 1.

An Rts1 derivative, pTW20, contains three incompatibility (inc) regions, incI-a (incI in previous studies), incII, and newly determined incI-b loci. By restriction analysis, we have located the incI-b adjacent to the incI-a region on the pTW20 map. Nucleotide sequence analysis of the minimal incI-b region revealed the presence of four repeated sequences, each consisting of 18 bp, which is similar to the incI-a and incII repeats existing on mini-Rts1. All four repeating units were required for expression of a strong incompatibility. In addition, RepA protein, essential for the replication of Rts1, bound specifically to the repeated sequences, suggesting that the repeats would titrate out RepA protein as do incI-a and IncII. Insertion of the incI-b to a mini-Rts1 plasmid in a natural arrangement decreases the copy number of mini-Rts1 to the same level as that of mini-F. The incI-a and incI-b might be a single constituent in incompatibility and copy number control of Rts1.

Base Sequence↗
PubMed1988

Importance of the C terminus of plasmid Rts1 RepA protein for replication and incompatibility of the plasmid.

RepA protein, essential for replication of plasmid Rts1, was found to bind in vivo immediately upstream of the repA promoter in studies with mini-Rts1 derivatives with deletions in the upstream region of repA. We constructed another series of repA mutants that would encode RepA derivatives containing oligopeptide substitutions in place of the carboxyl-terminal six amino acids. These modified RepA proteins could not activate ori (Rts1) at all and showed various degrees of incompatibility, or no incompatibility, toward a mini-Rts1 plasmid. These results suggest that the carboxyl-terminal six (or fewer) amino acids of RepA are important for exerting replication and incompatibility functions. One of the RepA derivatives, which showed an evident incompatibility without initiating replication, was examined for its ability to repress the repA gene.

Bacterial Proteins↗