Isolation, characterization, and localization of the spanning protein from skeletal muscle triads

A monoclonal antibody has been developed against the putative junctional protein or spanning protein (SP) from skeletal muscle triads. By immuno-affinity chromatography, we have purified this protein. The native protein has a molecular mass of 630-800 kD, as determined by gel filtration and rate zonal centrifugation. Within the limits of the methods used, the basic unit of the SP appears to be a dimer. In electron micrographs, it is shown to exhibit a circular profile with a diameter of approximately 100 A. In thin section analysis, the protein is frequently observed as parallel tracks of electron-dense particles bordering a translucent core. We suggest that the basic unit of the junctional structure is a dimer of 300-kD subunits and that four such entities constitute the intact SP. The purified protein has been used to develop polyclonal antibodies. By immunoelectron microscopy using immunogold probes, the SP has been localized to the junctional gap of the triad. By attaching the SP to an affinity resin, three proteins have been identified as forming associations with the SP. The Mrs of the proteins are 150, 62, and 38 kD; the 62-kD protein is calsequestrin.     

Bulk movement included in multi-channel mechanomyography: Similarity between mechanomyography of resting muscle and that of contracting muscle

Although mechanomyography (MMG) reflects local vibrations from contracting muscle fibers, it also includes bulk movement: deformation in global soft tissue around measuring points. To distinguish between them, we compared the multi-channel MMG of resting muscle, which dominantly reflected the bulk movement caused by arterial pulsations, to that of the contracting muscle. The MMG signals were measured at five points around the upper arms of 10 male subjects during resting and during isometric ramp contraction from 5% to 85% of maximal voluntary contraction (MVC) of the biceps brachii muscle. The characteristics of bulk movement were defined as the amplitude distribution and phase relation among the five MMG signals. The bulk movement characteristics during the rest state were not necessarily the same among the subjects. However, below 30 Hz, each subject’s characteristics remained the same from the rest state (0% MVC) to the contracting state (80% MVC), at which the bulk movement mainly originates from muscle contraction activity. Results show that the MMG of the low frequency domain (<30 Hz) includes bulk movement depending on the mechanical deformation characteristics of each subject’s body, for a wide range of muscle contraction intensities.     

Lysophosphatidic acid acyltransferase from the thermophilic bacterium Thermus thermophilus HB8 displays substrate promiscuity

ABSTRACT

Lysophosphatidic acid acyltransferase is a phospholipid biosynthetic enzyme that introduces a fatty acyl group into the sn-2 position of phospholipids. Its substrate selectivity is physiologically important in defining the physicochemical properties of lipid membranes and modulating membrane protein function. However, it remains unclear how these enzymes recognize various fatty acids. Successful purification of bacterial lysophosphatidic acid acyltransferases (PlsCs) was recently reported and has paved a path for the detailed analysis of their reaction mechanisms. Here, we purified and characterized PlsC from the thermophilic bacterium Thermus thermophilus HB8. This integral membrane protein remained active even after solubilization and purification and showed reactivity toward saturated, unsaturated, and methyl-branched fatty acids, although branched-chain acyl groups are the major constituent of phospholipids of this bacterium. Multiple sequence alignment revealed the N-terminal end of the enzyme to be shorter than that of PlsCs with defined substrate selectivity, suggesting that the shortened N-terminus confers substrate promiscuity.     

Relation between psychosocial variables and the glycemic control of patients with type 2 diabetes: A cross-sectional and prospective study

Background  

This cross-sectional and prospective study used a variety of psychological inventories to evaluate the relationship between psychosocial factors and the glycemic control of patients with type 2 diabetes.     

Isocyanurates with Planar Chirality: Design,Optical Resolution,and Isomerization

Designs and syntheses of isocyanurates ( 1–3 ) are described on the basis of a novel concept that two enantiotopic faces of C_s‐symmetric, prochiral planar molecules are differentiated with a location of groups at the top or bottom of the planar skeleton using a rigid linker. Such isocyanurates are atropisomeric. The planar‐chiral structures of 1 and 2 _anti (anti‐conformer of 2 ) were confirmed by single‐crystal X‐ray analyses, and the space groups were P1 (for 1 ) and P2₁/c (for 2 _anti), resulting that the crystals were racemates. Optical resolutions of 1–3 were successfully accomplished by using chiral high‐performance liquid chromatography technique in combination with circular dichroism, absorption, and nuclear magnetic resonance spectroscopies and mass spectrometry. Furthermore, the rotational barriers (ΔG^?s) related to isomerizations of 1–3 were estimated to be 27.2 (for 1 at 50 °C), 27.6 (for 2 _anti at 50 °C), and 40.6 (for 3 _syn at 150 °C) kcal/mol. The ΔG^?s of 2 and 3 were higher than that of 1 and, in particular, that of 3 was highest among them. This result indicates that an introduction of bulky substituents and an intramolecular bridging are effective for inhibitions of the isomerizations. Chirality 00:000–000, 2012. © 2012 Wiley Periodicals, Inc.     

Serotype analysis of group A human rotavirus related to acute gastroenteritis in winter in Gifu city

A total of 348 fecal specimens collected from children with acute gastroenteritis in Gifu city over three consecutive winter seasons (from November 1986 to March 1989) were examined for group A human rotavirus (HRV) by either a commercial test kit or a sandwich enzyme-linked immunosorbent assay (sandwich ELISA). One hundred twelve of the 173 group A HRV-positive specimens were further subjected to serotype determination by ELISA with four serotype-specific monoclonal antibodies to VP7 (ELISA-serotyping). Ninety-one specimens (81.3%) were successfully serotyped: 41 (36.6%) were serotype 1, 13 (11.6%) serotype 2, 27 (24.1%) serotype 3, and 10 (8.9%) serotype 4. The serotypes of the remaining 21 (18.8%) could not be determined. The predominant serotype of HRV that prevailed in Gifu city changed every winter: serotype 3 (63.4%) was most prevalent in the 1st winter, serotype 4 (42.9%) in the 2nd winter, and serotype 1 (64%) in the 3rd winter.     

Characterization of extracellular membrane vesicles of an Antarctic bacterium,Shewanella livingstonensis Ac10, and their enhanced production by alteration of phospholipid composition

Extremophiles - A cold-adapted bacterium, Shewanella livingstonensis Ac10, which produces eicosapentaenoic acid (EPA) as a component of its membrane phospholipids, is useful as a model to study the...