Alkaline phosphatase isozymes in the midgut of silkworm: purification of high pH-stable microvillus and labile cytosolic enzymes

Summary Genetically defined alkaline phosphatase (ALP) isozymes from the larval midgut tissues ofBombyx mori were purified and characterized. The membrane-bound form (m-ALP) was solubilized with 1% Triton X-100, then purified by DEAE-Sephacel, Con A-Sepharose 4B and Ultrogel AcA 34 column chromatography. The soluble form (s-ALP) was purified by DEAE-Sephacel, epoxy Toyopearl coupled with phosphonic acid and Ultrogel AcA 34 column chromatography. About 840- and 650-fold purification were achieved for m-ALP and s-ALP, respectively, and both ALPs were homogeneous as judged by poly-acrylamide gel electrophoresis. Both forms were found to be similar (MW=68 000 in gel permeation chromatography, and a single subunit as a monomer in denaturing SDS-polyacrylamide gels with MW=58 000 for m-ALP and MW=61 000 for s-ALP). The pH optima of ALPs were shown to lie at 10.9 (m-ALP) and 9.8 (s-ALP), the former being extremely stable even in pH 10–12 which accords with the physiological milieu inBombyx midgut lumen. The K_m values of the m-ALP and s-ALP forp-nitrophenyl phosphate were 1.99 and 1.49 mM, respectively. Both ALPs had a similar substrate specificity.l-Cysteine strongly inhibited both ALPs, but inhibitory effects ofl-phenylalanine,l-homoarginine andl-leucine were undetectable for s-ALP and very weak for m-ALP. A comparison of enzymatic properties on two ALPs suggested that each isozyme plays different roles.Abbreviations m-ALP membrane-bound alkaline phosphatase - s-ALP soluble alkaline phosphatase     

Immunocytochemical localization of cathepsin B in degenerating rat skeletal muscle induced by a local anesthetic, bupivacaine

Experimental acute degenerative changes in skeletal muscle accompanied by a drastic increase in cathepsins B&L were induced in rats by intramuscular injection of a local anesthetic, bupivacaine. Cathepsins B&L have been implicated in the rapid disappearance of muscle fibers. Degenerating muscle showed a spotty fluorescence when stained with antibodies against cathepsin B, indicating that the increased cathepsin B did not originate from the muscle itself, but from invading phagocytes. We report here results showing that cathepsin B of nonmuscle cell origin is involved in the breakdown of myofibrillar proteins in acute bupivacaine-induced muscle degeneration.     

Population abundance gradient of Inurois punctigera along altitude

A winter geometrid moth, Inurois punctigera, shows sympatric and genetically isolated seasonal populations (i.e. early‐ and late‐winter populations) in the cold regions of Japan, whereas it shows only mid‐winter populations in the warm regions. Variation in adult flight phenology on a large geographic scale along latitudinal environmental gradients has been described, but the phenological variation on a more local scale along altitudinal environmental gradients has not yet been characterized. In the present study, we assessed the flight phenology at high‐ and low‐elevation areas in Mt. Rokko, Hyogo, Japan. First, we revealed that flight period was not disrupted in mid‐winter, even at high‐elevation areas (>660 m) but the population abundance was much lower in high‐elevation areas than in low‐elevation areas. Then, in the following two seasons, we investigated I. punctigera abundance, winter harshness (i.e. winter temperature) and their host plant abundance in nine closely located stations in Mt. Rokko. A generalized linear mixed model analysis indicated a greater effect of winter temperature on I. punctigera abundance compared to available food resources, suggesting that differences in winter harshness among elevation shapes the gradient of I. punctigera abundance along altitude. Our findings suggest that harsh conditions during winter function as selective agents on mid‐winter types of I. punctigera, and this could be involved in the divergence between sympatric early‐ and late‐winter populations of I. punctigera.     

A Geometry-Based Multiple Testing Correction for Contingency Tables by Truncated Normal Distribution

Statistics in Biosciences - Inference procedure is a critical step of experimental researches to draw scientific conclusions especially in multiple testing. The false positive rate increases unless...     

Development of near-infrared firefly luciferin analogue reacted with wild-type and mutant luciferases

Interestingly, only the D-form of firefly luciferin produces light by luciferin–luciferase (L–L) reaction. Certain firefly luciferin analogues with modified structures maintain bioluminescence (BL) activity; however, all L-form luciferin analogues show no BL activity. To this date, our group has developed luciferin analogues with moderate BL activity that produce light of various wavelengths. For in vivo bioluminescence imaging, one of the important factors for detection sensitivity is tissue permeability of the number of photons emitted by L–L reaction, and the wavelengths of light in the near-infrared (NIR) range (700–900 nm) are most appropriate for the purpose. Some NIR luciferin analogues by us had performance for in vivo experiments to make it possible to detect photons from deep target tissues in mice with high sensitivity, whereas only a few of them can produce NIR light by the L–L reactions with wild-type luciferase and/or mutant luciferase. Based on the structure–activity relationships, we designed and synthesized here a luciferin analogue with the 5-allyl-6-dimethylamino-2-naphthylethenyl moiety. This analogue exhibited NIR BL emissions with wild-type luciferase (λ_max = 705 nm) and mutant luciferase AlaLuc (λ_max = 655 nm).     

Reduction of severe acute respiratory syndrome coronavirus-2 infectivity by admissible concentration of ozone gas and water

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the global coronavirus disease 2019 (COVID-19) pandemic. Because complete elimination of SARS-CoV-2 appears difficult, decreasing the risk of transmission is important. Treatment with 0.1 and 0.05 ppm ozone gas for 10 and 20 hr, respectively, decreased SARS-CoV-2 infectivity by about 95%. The magnitude of the effect was dependent on humidity. Treatment with 1 and 2 mg/L ozone water for 10 s reduced SARS-CoV-2 infectivity by about 2 and 3 logs, respectively. Our results suggest that low-dose ozone, in the form of gas and water, is effective against SARS-CoV-2.     

Comparison of neuronal responses in primate inferior-temporal cortex and feed-forward deep neural network model with regard to information processing of faces

Journal of Computational Neuroscience - Feed-forward deep neural networks have better performance in object categorization tasks than other models of computer vision. To understand the relationship...