Relationship between the stability of lysozymes mutated at the inside hydrophobic core and secretion in Saccharomyces cerevisiae

The relationship between the stability of lysozymes mutated at the inside hydrophobic core and secretion was investigated to understand the optimal secretion of mutant lysozymes in the Saccharomyces cerevisiae. S91T mutant lysozyme increased in the methyl residue inside the core greatly increased the conformational stability. The secretion amount of S91T in S. cerevisiae increased greatly compared with wild-type lysozyme. On the other hand, I55V and T40S/I55V mutant lysozymes decreased in methyl residue inside the core brought about their unstable conformation. The secretion amounts of these unstable mutant lysozymes significantly decreased. In addition, the effect of glycosylation on the secretion of these mutants was investigated. The secretion amounts of glycosylated lysozyme S91T/G49N with stable hydrophobic core greatly increased compared with that of glycosylated lysozyme G49N, while those of mutant I55V/G49N and T40S/I55V/G49N with unstable hydrophobic core greatly decreased. These results indicate that the secretion amounts of mutant lysozymes increase in proportion to the hydrophobic core stabilities and that a similar good correlation was obtained with glycosylated lysozymes.     

A 100-Gb/s throughput ATM switch MCM with a 320-channel paralleloptical I/O interface

For an ATM switch system, we have developed a 100-Gb/s input/output (I/O) throughput optical I/O interface ATM switch multichip module (MCM) that has 320-ch optical I/O ports. This MCM is fabricated using ceramic (MCM-C) technology and very-small highly-parallel O/E and E/O optical converters. It uses 0.25-μm complementary metal oxide semiconductors (CMOS) ATM switch large scale integrations (LSIs) and has a total I/O throughput of up to 160 Gb/s. A prototype module with total I/O throughput of 100 Gb/s has been partially assembled using eight optical I/O interface blocks, each composed of a 40-ch O/E converter and a 40-ch E/O converter; the data rate per channel is from dc to 700 Mb/s. Using this module we developed an optical I/O interface ATM switch system and confirmed the operation of the optical interface     

Methanol synthesis from carbon dioxide at atmospheric pressure over Cu/ZnO catalyst. Role of methoxide species formed on ZnO support

Methanol synthesis from CO₂ and H₂ was carried out over a Cu/ZnO catalyst (Cu/Zn = 3/7) at atmospheric pressure, and the surface species formed were analyzed by diffuse reflectance FT-IR spectroscopy and temperature programmed desorption method. Two types of formate species and zinc methoxide were formed in the course of the reaction. Zinc methoxide was readily hydrolyzed to methanol. H₂O formed through the reverse water gas shift reaction was suggested to be involved in the hydrolysis of zinc methoxide.     

Anode properties of Ru-coated Si thick film electrodes prepared by gas-deposition

Thick film electrodes consisting of Ru and Ru-coated Si particles were fabricated by a gas-deposition method and their electrochemical properties of anodes for Li rechargeable battery were evaluated. The discharge capacity of the Ru electrode at 1000th cycle is approximately 400 mAh g⁻¹. The result showed that the electrode reaction is based on the redox reaction of RuO₂ which was formed on the Ru surface during the charge-discharge processes. By coating Si particles with Ru using an electroless deposition technique, we obtained an electrode with remarkable discharge capacity of 570 mAh g⁻¹ at 1000th cycle. The reason for the improvement in the electrode performance appears to result from the fact that the Ru electrode exhibits excellent cycleability itself and the Ru coated on Si reduces the stress generated by the immense volumetric changes occurring in the Si particles.     

Identification and determination of unknown chemicals in crops by dual-column GC system equipped with MS and ECD

A dual-column GC system equipped with MS and ECD, using two identical columns (HP-1701), one connected to the MS and one to the ECD, has been developed. The carrier gas flow rate was adjusted to give the same retention time of each peak in both columns. Unknown peaks were detected and identified in 7 samples of crops using this system. It was confirmed that the unknown peaks were 5 pesticides, i.e., bromopropylate and others. The recoveries and CV of bromopropylate from spinach and Komatsuna were good. The results of determination of bromopropylate by both MS and ECD were the same. Unknown chemicals can be easily identified using GC equipped with MS and ECD, and this system should be useful in the field of food hygiene.     

Some biochemical properties of the components of Staphylococcus aureus binding to human platelets

The purpose of this study was to ascertain whether pulmonary function in children who were lifetime residents of the highly polluted district of Teplice in northern Bohemia was lower than that for children who were lifetime residents of the cleaner district of Prachatice in southern Bohemia. Forced expiratory spirometry was measured twice (February/March and April) in approximately 235 eighth-grade students in each district. On both testing occasions, height-adjusted forced expiratory volume in 1 s and forced expiratory flow between 25% and 75% forced vital capacity were significantly lower (p < .001) in children from Teplice than in those from Prachatice. These differences were not associated with parental smoking habits, presence of pets, heating/cooking fuels, private home/apartment residency, or rural/urban residency. In Teplice, no differences were observed between lung functions measured at the end of the high pollution season (February/March) and those measured after the children breathed much cleaner air for a 4-wk period (April). This result was suggestive of a condition of chronically depressed lung function. No differences across times were observed in Prachatice, indicating that our measurements were reliable.     

Inhibition of NO synthesis induces inflammatory changes and monocyte chemoattractant protein-1 expression in rat hearts and vessels

We recently showed that chronic inhibition of NO synthesis by N(omega)-nitro-L-arginine methyl ester (L-NAME) causes coronary vascular remodeling (ie, vascular fibrosis and medial thickening) in rats. To test the hypothesis that the inhibition of NO synthesis induces inflammatory changes in the heart, we characterized the inflammatory lesions that occurred during L-NAME administration and determined whether inflammation involved the induction of monocyte chemoattractant protein-1 (MCP-1) in vivo. During the first week of L-NAME administration to Wistar-Kyoto rats, we observed a marked infiltration of mononuclear leukocytes (ED1-positive macrophages) and fibroblast-like cells (alpha-smooth muscle actin-positive myofibroblasts) into the coronary vessels and myocardial interstitial areas. These inflammatory changes were associated with the expression of proliferating cell nuclear antigen and MCP-1 (both mRNA and protein). The areas affected by inflammatory changes, as well as the expression of MCP-1 mRNA, declined after longer (28 days) treatment with L-NAME and were replaced by vascular and myocardial remodeling. Our results support the hypothesis that the inhibition of NO synthesis induces inflammatory changes in coronary vascular and myocardial tissues and involves MCP-1 expression. Results also suggest that the early stages of inflammatory changes are important in the development of later-stage structural changes observed in rat hearts.     

A basic study of photodynamic therapy of experimental hepatoma with ME 2906

We have studied effects of photodynamic diagnosis (PDD) and photodynamic therapy (PDT) in hepatoma as confirmed by the existence of hepatoma when using a new photosensitizer mono-L-aspartyl chlorin e6. Japanese white rabbits were selected to perform abdominal incision under intravenous anesthesia and transplant VX2 tumor cells into the liver left lobe for the hepatoma model. Hepatoma of 1 cm in diameter (at one week after transplantation) was used experimentally to radiate a semiconductor laser (664 nm, 200 J/cm2) for treatment.