Extracellular localization of a nonfimbrial hemagglutinin of Yersinia pseudotuberculosis.

A nonfimbrial hemagglutinin (HA) of Yersinia pseudotuberculosis was observed by immunoelectron microscopy using monospecific HA antiserum and protein A-gold conjugate. The HA, an amorphous but morphologically identifiable entity, was located in a region distal to or detached from the outer edge of bacteria.     

Ulex Europaeus Agglutinin-1 Is a Reliable Taste Bud Marker for In Situ Hybridization Analyses

Taste signals are received by taste buds. To better understand the taste reception system, expression patterns of taste-related molecules are determined by in situ hybridization (ISH) analyses at the histological level. Nevertheless, even though ISH is essential for determining mRNA expression, few taste bud markers can be applied together with ISH. Ulex europaeus agglutinin-1 (UEA-1) appears to be a reliable murine taste bud marker based on immunohistochemistry (IHC) analyses. However, there is no evidence as to whether UEA-1 can be used for ISH. Thus, the present study evaluated UEA-1 using various histochemical methods, especially ISH. When lectin staining was performed after ISH procedures, UEA-1 clearly labeled taste cellular membranes and distinctly indicated boundaries between taste buds and the surrounding epithelial cells. Additionally, UEA-1 was determined as a taste bud marker not only when used in single-colored ISH but also when employed with double-labeled ISH or during simultaneous detection using IHC and ISH methods. These results suggest that UEA-1 is a useful marker when conducting analyses based on ISH methods. To clarify UEA-1 staining details, multi-fluorescent IHC (together with UEA-1 staining) was examined, resulting in more than 99% of cells being labeled by UEA-1 and overlapping with KCNQ1-expressing cells.     

Isolation, and morphological and chemical properties of an autolysis-deficient mutant of Clostridium botulinum type A.

An autolysis-deficient mutant was isolated from Clostridium botulinum type A 190L by treatment with ethyl methanesulfonate. The cell wall prepared from the mutant autolyzed at much slower rate than that from the parent strain, accompanying with much less liberation of both amino terminals and reducing groups. Electron microscopic observation revealed that the mutant strain was converted to short rod or curved spherical form with thickened cell walls when the growth temperature was shifted from 37 to 45 C. The mutant had a significantly larger amount of non-peptidoglycan-carbohydrate complexes than did the parent strain and became markedly resistant to the autolysin partially purified from the parent, compared with the parent strain. Furthermore, the mutant was fairly tolerant to killing by penicillin. These results suggest that the autolysis deficiency of the mutant was due not only to the deficient production of autolysin but also to the excess accumulation of carbohydrate in the cell wall.     

Extremely high intracellular concentration of glucose-6-phosphate and NAD(H) in Deinococcus radiodurans

Extremophiles - Deinococcus radiodurans is highly resistant to ionizing radiation and UV radiation, and oxidative stress caused by such radiations. NADP(H) seems to be important for this resistance...     

Autolytic Enzyme System of Clostridium botulinum

Isolated cell walls of Clostridium botulinum type A strain 190L released an autolysin during autolysis of the cell walls. The autolysin was isolated from the cell walls, and partially purified 18.6-fold by ammonium sulfate precipitation, chromatography on DEAE-cellulose and gel filtration through Sephadex G-100. The purified preparation of the autolysin showed 2 major and 2 minor protein bands on Polyacrylamide gel electrophoresis. Some properties of the autolysin were examined using SDS-treated cell walls of the organisms as a substrate. The autolysin was active over a pH range of 6 to 8, with a maximum near pH 6.8. The lytic activity was stimulated by 10^?4 M each of Co⁺⁺, Mg⁺⁺ and Ca⁺⁺ in the order, whereas it was inhibited markedly by Cu⁺⁺. Mercaptoethanol (10^?4–10^?3 M) significantly activated the lytic action. Trypsin and nagarse (10 μg/ml) also stimulated the lytic activity. The lytic spectrum of the autolysin toward the SDS-treated cell walls obtained from various types of C. botulinum and C. perfringens indicated a relatively high specificity. After treatment with hot formamide the cell walls of C. botulinum increased in susceptibility to the autolysin.