The phagocyte NADPH oxidase, dormant in resting cells, is activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants. The activated oxidase is a complex of membrane-integrated cytochrome bs58, composed of 91-kDa (gp91PbOx) and 22-kDa (p22PIox) subunits, and two cytosolic factors (p47PbOX and p67Pb°'), each containing two Src homology 3 (SH3) domains.Here we show that the region of the tandem SH3 domains of p47Phox (p47-SH3) expressed as a glutathione S-transferase fusion protein inhibits the superoxide production in a cell-free system, indicating involvement of the domains in the activation. Furthermore, we find that arachidonic acid and sodium dodecyl sulfate, activators of the oxidase in vitro, cause exposure of p47-SH3, which has probably been masked by the C-terminal region of this protein in a resting state. The unmasking of p47-SH3 appears to play a crucial role in the assembly of the oxidase components, because p47-SH3 binds to both p22PhO and p67PhOx but fails to interact with a mutant p22Phox carrying a Pro-156 -* Gln substitution in a prolinerich region, which has been found in a patient with chronic granulomatous disease. Based on the observations, we propose a signal-transducing mechanism whereby normally inaccessible SH3 domains become exposed upon activation to interact with their target proteins.During ingestion of microbes or upon stimulation with various soluble molecules, neutrophils and other phagocytic cells produce superoxide (O°), a precursor of microbicidal oxidants (1-4). The process involves activation ofthe phagocyte NADPH oxidase, dormant in resting cells, that catalyzes reduction of molecular oxygen to superoxide in conjunction with oxidation of NADPH. The significance of the NADPH oxidase in host defense is made evident by recurrent and life-threatening infections that occur in patients with chronic granulomatous disease (CGD) whose phagocytes lack the superoxide-producing system (1-4).The active NADPH oxidase is found on the phagocyte membrane as an enzyme complex, the components ofwhich are identified as targets of genetic defects causing CGD. The one identified at an earlier stage is a phagocyte-specific membrane-integrated b-type cytochrome, cytochrome b558 (5-11), composed of 91-kDa and 22-kDa subunits (designated gp91Phox and p22PhOX, respectively). The cytochrome is now considered to be a flavocytochrome comprising an apparatus transporting electrons from NADPH via FAD and then heme to molecular oxygen (12)(13)(14)(15)(16) . In addition to these specialized factors, as a third cytosolic factor, the small GTPbinding protein p21rac (rac 1 and/or rac 2) is also involved in the system (22)(23)(24).Although the components of the NADPH oxidase are thus identified, little is known about the mechanism for their assembly leading to activation of the enzyme. Upon phagocyte stimulation, the cytosolic components translocate to the membrane where cytochrome b558 resides (25,26). Experiments using neutrophils from CGD patients have revealed that the t...

Micellization kinetics of poly(a-methylstyrene)-6Zoc^-poly(vinylphenethyl alcohol) (PoMS-¿-PVPA) in selective solvent, benzyl alcohol (BA), was investigated by time-resolved static and dynamic

Abstract-This paper describes a speaker-adaptive HMM-based speech synthesis system. The new system, called "HTS-2007," employs speaker adaptation (CSMAPLR+MAP), feature-space adaptive training, mixed-gender modeling, and full-covariance modeling using CSMAPLR transforms, in addition to several other techniques that have proved effective in our previous systems. Subjective evaluation results show that the new system generates significantly better quality synthetic speech than speaker-dependent approaches with realistic amounts of speech data, and that it bears comparison with speaker-dependent approaches even when large amounts of speech data are available. In addition, a comparison study with several speech synthesis techniques shows the new system is very robust: It is able to build voices from less-than-ideal speech data and synthesize good-quality speech even for out-of-domain sentences.

ABSTRACT:Solid-state structures of comb-like polyacrylates (PAx) and polymethacrylates (PMx) having crystallizable n-octadecyl side chains and their blends with n-octadecanoic acid (Cl8) have been investigated by means of differential scanning calorimetry and X-ray diffraction methods. It is concluded that n-alkyl side chains of comb-like polymer cocrystallize with low-molecular-weight Cl8 by incorporation of Cl8 into hexagonal crystalline lattice. In the case of amorphous PMx, the addition of Cl8 can induce a formation of crystalline domain by the cocrystallization with the side chain. Differences in the crystallization behavior, such as fractions of crystallized methylene units and effects of thermal history, between PAx and PMx are found to be considerably large. These results are explained by the difference in the segmental mobility of main chain.KEY WORDS Comb-Like Polymer/ n-Octadecanoic Acid/ Cocrystallization / X-Ray Diffraction/ DSC Measurement / n-Alkyl Side Chain / Differences in solid-state nature between side chain and main chain in comb-like polymers are anticipated to give a wide variety of phases, structures, and morphologies, for example, those in side-chain liquid crystalline polymers 1 and rigid-rod polymer with flexible side chains. 2 -4 Comb-like polymers, which have crystallizable long n-alkyl side chains being attached to amorphous main chain, are known to pack into layered structure with alternating crystalline side-chain region and amorphous main-chain region in the solid state. 5 -13 Plate and Shibaev 6 studied these comb-like polymers extensively. X-Ray diffraction profile for such polymer has an intense reflection corresponding to the Bragg spacing d of 4.2 A, which suggests a formation of hexagonal crystalline lattice of n-alkyl side chain. There also exists a reflection in smaller angle region, which is considered to originate from the layered structure. The repeating distance of crystalline-amorphous layer can be obtained by the diffraction angle of this reflection. Plate et al. 6 observed striking difference in the diffraction patterns and layer spacings between comb-like polyacrylates and polymethacrylates. In order to interpret this difference, they proposed two models for chain packing: two-layer structure and one-layer structure for respective polymers. In the former model, the side chains are extended on both side of the main chain and these polymers pack closely because of the flexibility of the main chain. In the latter structure, the disordered packing of the end groups of side chains occurs because of the increased bulkiness of the main chain, and the polymer chains are arranged with a shift toward the extended side-chain axis. Later, Hsieh et al. 9 proposed a new structural model for the solid state poly(n-octadecyl methacrylate), where the side-chain crystallites are formed by intercalating side chains pointing in opposite directions. Although the detailed solid-state structures of these comb-like polymers have not been clarified as yet, the layered structure with the...

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