Characterization of a cry2A Gene Cloned from an Isolate of Bacillus thuringiensis serovar sotto

A cry2A-type gene, designated as cry2(SKW), was cloned from Bacillus thuringiensis serovar sotto SKW01-10.2-06, and some unique features of the gene were revealed. The cry2(SKW) gene encoded a polypeptide of 635 residues with a predicted molecular mass of 71,137 Da. Cry2(SKW) had 95.4% identity with Cry2Aa in amino acid sequence and was two residues longer than Cry2Aa. Two open reading frames (ORFs), designated as orf1 and orf2, were present upstream of the cry2(SKW) and showed high homology with the corresponding ORFs in the cry2Aa operon. The Orf2 from SKW01-10.2-06 contained a region of repeated sequences. However, unlike Cry2Aa, Cry2(SKW) formed the cuboidal crystalline inclusions when the cry2(SKW) gene was expressed in an acrystalliferous B. thuringiensis strain in the absence of the upstream ORFs. Furthermore, Cry2(SKW) was less toxic to a lepidopteran species, Bombyx mori, than Cry2Aa in spite of high homology between the two proteins. Received: 17 July 1996 / Accepted: 5 December 1996     

Comparative Studies on Functions of Human Adenovirus Type 12 and Its Low Oncogenic Mutant Virions

Physical and biological properties of highly oncogenic human adenovirus type 12 were compared with a low oncogenic mutant (cyt mutant). Parental and cyt mutant virions had very similar density and DNA size. However, the parental strain virion preparations contained a much higher proportion of defective virions (capable of cell killing, but not able to induce T- or V-antigen) than cyt mutant stock. It was also found that cyt mutant had a reduced virus yield in several human cell lines compared with the parental strain.     

Prevalence of human T‐lymphotropic virus type 1 carriers among pregnant women in Hokkaido,Japan

As there is a risk of MTCT of HTLV‐1, the HSGP HTLV‐1 MTCT was organized in 2011. To determine how many pregnant women are infected with HTLV‐1 in Hokkaido, which is the northernmost and the second largest island in Japan with a population of 5 467 000 and 39 392 newborns in 2011, the HSGP HTLV‐1 MTCT asked all facilities that may care for pregnant women in Hokkaido in July 2013 to provide information on the number of pregnant women who underwent screening for anti‐HTLV‐1 antibody using particle agglutination or chemiluminescent enzyme immunoassay, and the numbers of those with positive, equivocal, and negative test results in the screening and confirmation tests using western blotting or PCR methods in 2012, respectively. A total of 111 facilities participated in this study and provided information on 33 617 pregnant women who underwent screening in 2012, corresponding to approximately 85% of all pregnant women who gave birth in Hokkaido in 2012. Of 81 candidates for a confirmation test because of positive (n = 77) or equivocal (n = 4) results on screening, 63 (78%) underwent the confirmation test and, finally, 34 (0.1%) and 33 563 (99.8%) women were judged to be HTLV‐1 carriers and non‐carriers, respectively. It was concluded that the prevalence rate of HTLV‐1 carriers was low, one per 1000 pregnant women in Hokkaido. Approximately 40 infants are born yearly to mothers infected with HTLV‐1 in Hokkaido.     

Increased superoxide radicals generation from alveolar macrophages in immature guinea-pigs

To study the effect of maturation on abilities of superoxide radicals (O-2) generation in the airways, we compared stimuli-induced O-2 generation by alveolar macrophages in immature (aged 10+/-2 days) and adult (aged 90+/-2 days) guinea-pigs. The production of O-2 was assayed by chemiluminescence method, using a Cypridina luciferin analog as a highly sensitive and specific probe for O-2. Whereas no significant difference in cell components of bronchoalveolar lavage fluid was observed between immature and adult animals, O-2 generation induced by stimulation of alveolar macrophages was greater in immature than in adult animals, with significant differences observed after platelet-activating factor (100 nM) or phorbol myristate acetate (0.5 micro g/ml). The results suggest that alveolar macrophages from immature animals are far more potent O-2 generators than the same cells of adult animals.     

Unusual hydrophobic linker region of β-glucosidase (BGLII) from Thermoascus aurantiacus is required for hyper-activation by organic solvents

A gene encoding a putative β-glucosidase was isolated from Thermoascus aurantiacus IFO9748 and designated as bgl2. The recombinant enzyme showed β-glucosidase activity when p-nitrophenyl-β-glucose (pNP-Glc) was used as substrate. We also found that the enzyme activity was increased in the presence of organic solvents. An addition of 20 % (v/v) 1-octanol resulted in 54-fold higher activity of pNP-Glc hydrolysis, and transglycosylation activity was also found to be activated. The results of tryptophan fluorescence spectral analysis revealed the changes in the tertiary structure of the enzyme in the presence of 1-hexanol that may cause increased enzyme activity. BGLII has a distinctive hydrophobic linker region between N- and C-terminal domains. A chimeric enzyme in which the linker region was substituted by the corresponding region of another β-glucosidase failed to be activated by organic solvents, suggesting that the hydrophobic linker region may act as a molecular switch in BGLII.     

Two functional sites of phosphatidylglycerol for regulation of reaction of plastoquinone QB in photosystem II

Functional roles of an anionic lipid phosphatidylglycerol (PG) were studied in pgsA-gene-inactivated and cdsA-gene-inactivated/phycobilisome-less mutant cells of a cyanobacterium Synechocystis sp. PCC 6803, which can grow only in PG-supplemented media. 1) A few days of PG depletion suppressed oxygen evolution of mutant cells supported by p-benzoquinone (BQ). The suppression was recovered slowly in a week after PG re-addition. Measurements of fluorescence yield indicated the enhanced sensitivity of Q_B to the inactivation by BQ. It is assumed that the loss of low-affinity PG (PG_L) enhances the affinity for BQ that inactivates Q_B. 2) Oxygen evolution without BQ, supported by the endogenous electron acceptors, was slowly suppressed due to the direct inactivation of Q_B during 10 days of PG depletion, and was recovered rapidly within 10 h upon the PG re-addition. It is concluded that the loss of high-affinity PG (PG_H) displaces Q_B directly. 3) Electron microscopy images of PG-depleted cells showed the specific suppression of division of mutant cells, which had developed thylakoid membranes attaching phycobilisomes (PBS). 4) Although the PG-depletion for 14 days decreased the chlorophyll/PBS ratio to about 1/4, florescence spectra/lifetimes were not modified indicating the flexible energy transfer from PBS to different numbers of PSII. Longer PG-depletion enhanced allophycocyanin fluorescence at 683 nm with a long 1.2 ns lifetime indicating the suppression of energy transfer from PBS to PSII. 5) Action sites of PG_H, PG_L and other PG molecules on PSII structure are discussed.