The 3.0 A projection structure of microsomal glutathione transferase as determined by electron crystallography of p 21212 two-dimensional crystals

Two-dimensional crystals of rat microsomal glutathione transferase were grown during dialysis of detergent-solubilized enzyme after addition of a small amount of phospholipid. The crystals had two-sided plane group symmetry p21212 with a calibrated unit cell size of a=91.90 A, b=90.83 A. Electron diffraction patterns were recorded showing significant reflections extending to 3.0 A. A combination of these structure factor amplitudes with phases from high-resolution images following image processing was used to calculate a projection map of the protein. The asymmetric unit of the structure consists of three microsomal glutathione transferase molecules. The local 3-fold axis at the center of the trimer is delineated by six parallel alpha-helices, two from each monomer. The two helices differ significantly in their respective projection structure. The inner helical core of the trimer is partly surrounded by elongated domains with extensions towards the helices and which contain resolved density maxima at a spacing of 4 to 5 A. A well-defined strong peak is localized close to the elongated domain and at a distance of about 9.5 A from two of the inner helices.     

Electron microscopy of tRNA crystals: I. Thin crystals negatively stained with uranyl acetate

The first attempt to study crystal structures of tRNA by electron microscopy is described. Sufficiently thin crystals were prepared from yeast tRNA^phe. The thickness of the thinnest was estimated at 130 Å corresponding to a bilayer of the molecules. The L-shaped structure seemed to be maintained even after the negative staining with uranyl acetate. Optically filtered images from electron micrographs were compared with those simulated from the drawing of the molecular model by optical transform. The results suggest that the observed images reflect the real molecular arrangements within the crystal lattice although the shape of tRNA molecules seems to be somewhat modified by the uneven staining.     

Novel cephalosporin derivatives possessing a bicyclic heterocycle at the 3-position. Part II: Synthesis and antibacterial activity of 3-(5-methylthiazolo[4,5-c]pyridinium-2-yl)-thiomethylcephalosporin derivatives and related compounds

A series of cephalosporin derivatives with a thiazolopyridinium group at the 3-position was synthesized and evaluated for antibacterial activity. Some of these cephalosporin derivatives having a (5-alkylthiazolo[4,5-c]pyridinium-2-yl)thiomethyl group at the 3-position showed strong activity against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa. Among them, 5a showed a good antibacterial spectrum in vitro, and also showed a similar or slightly superior activity to that of ceftazidime in vivo against P. aeruginosa.     

A case of a patient diagnosed with malignant mixed Müllerian tumor of the ovary who conceived after conservative surgery and adjuvant chemotherapy

A case of successful pregnancy after treatment of stage Ia malignant mixed Müllerian tumor of the ovary is described. This tumor is very rare and usually occurs in postmenopausal women. cis-platinum-based chemotherapy following the primary operation in the early stage is the most effective treatment, although most of the tumors have been found in the advanced stage. In this patient, treatment with unilateral salpingo-oophorectomy to preserve fertility was performed and followed by cis-platinum-based chemotherapy for 5 years. Two years after completion of the chemotherapy, she spontaneously conceived and the course of the pregnancy has been uneventful to this point.     

Merits of heat assist for melt laser annealing

In this paper, the potential for sub-10-nm junction formation of partial-melt laser annealing (PMLA), which is a combination of solid-phase regrowth and heat-assisted laser annealing (HALA), is demonstrated. HALA and PMLA are effective for reducing laser-energy density for dopant activation and for improving heating uniformity of device structure. The absence of melting at the dopant profile tail for PMLA results in a negligibly small diffusion at this region. A high activation rate is achievable by melting the upper part of the amorphous-silicon layer. The obtained sheet resistance of 10-nm-deep junctions was about 700 /spl Omega//sq. for both n/sup +//p and p/sup +//n junctions. These results imply that PMLA is applicable for much shallower junction formation.     

High‐speed analysis of the major components of fatty acid methyl esters by capillary gas chromatography

We tested different column temperatures and carrier gas linear velocities in a capillary GC system with a high‐resolution column, DB‐23, to determine the shortest run time for analyzing the major components of a fatty acid methyl ester sample from any lipid source. Depending on the sample, the run time is 2 min or less. Commercially‐available high‐resolution columns can be used without modification.     

Biochemical and genetic characterization of a D(-)-3-hydroxybutyrate dehydrogenase from Acidovorax sp. strain SA1

D(-)-3-hydroxybutyrate dehydrogenase (BDH; EC 1.1.1.30) from a poly(D(-)-3-hydroxybutyrate) (PHB) degrading bacterium, Acidovorax sp. SA1, was purified using Toyopearl DEAE-650M, red-Sepharose CL-4B, and Q Sepharose FF. The molecular mass of the enzyme was estimated as 27 kDa by SDS-PAGE and 110 kDa by gel filtration. The gene encoding BDH was cloned and sequenced, and expressed in Escherichia coli. The gene product was purified in two steps with a high yield. The N-terminal amino acid sequence of the enzyme purified from E. coli agreed with that of the purified enzyme from strain SA1. The BDH of strain SA1 had high amino acid sequence homology to that of Ralstonia eutropha H16. The Km values for D(-)-3-hydroxybutyrate and NAD+ in the oxidation reaction were 4.5 x 10(-4) M and 8.9 x 10(-5) M, respectively. The Km values for acetoacetate and NADH in the reduction reaction were 2.4 x 10(-4) M and 2.9 x 10(-5) M, respectively.     

A convenient method for determination of the C20-22 PUFA composition of glycerolipids in blood and breast milk

A convenient method was developed for preparation of FAME in small amounts from glycerolipids of blood or breast milk. Initially, 0.04–0.06 mL blood or breast milk was spotted onto a small piece of filter paper (1.5×1.5 cm) that had been washed with acetone containing 0.05% 2,6-di-tert-butyl-p-cresol (BHT). Fach piece, once it had dried, was put in a small test tube, to which 2 mL hexane and 0.2 mL 2 M KOH/methanol were added. After vigorous mixing or sonication for 2 min at room temperature, the solution was neutralized or acidified by the addition of a few drops of acetic acid. To the solution was added 2 mL H₂O, and then the hexane layer that separated was concentrated to dryness in vacuo. The FAME obtained were analyzed by GC. The method was applicable to the analysis of a large number of blood and breast milk samples, and the arachidonate/(eicosapentaenoate +docosahexaenoate) ratios could be determined rapidly.