Gluten hydrolyzing activity of Bacillus spp isolated from sourdough.

BACKGROUND: Celiac disease is an intestinal chronic disorder with multifactorial etiology resulting in small intestinal mucosal injuries and malabsorption. In genetically predisposed individuals with HLA DQ2/DQ8 molecules, the gluten domains rich in glutamine and proline present gluten domains to gluten reactive CD4+ T cells causing injury to the intestine. In the present experimental design, the indigenous bacteria from wheat samples were studied for their gluten hydrolyzing functionality. RESULTS: Proteolytic activity of Bacillus spp. was confirmed spectrophotometrically and studied extensively on gliadin-derived synthetic enzymatic substrates, natural gliadin mixture, and synthetic highly immunogenic 33-mer peptide. The degradation of 33-mer peptide and the cleavage specificities of the selected isolates were analyzed by tandem mass spectrometry. The gluten content of the sourdough fermented by the chosen bacterial isolates was determined by R5 antibody based competitive ELISA. All the tested isolates efficiently hydrolyzed Z-YPQ-pNA, Z-QQP-pNA, Z-PPF-pNA, and Z-PFP-pNA and also cleaved 33-mer immunogenic peptide extensively. The gluten content of wheat sourdough was found to be below 110 mg/kg. CONCLUSION: It has been inferred that four Bacillus spp especially GS 188 could be useful in developing gluten-reduced wheat food product for celiac disease prone individuals.

Radiative Rotational Lifetimes and State-Resolved Relative Detachment Cross Sections from Photodetachment Thermometry of Molecular Anions in a Cryogenic Storage Ring.

Photodetachment thermometry on a beam of OH^{-} in a cryogenic storage ring cooled to below 10 K is carried out using two-dimensional frequency- and time-dependent photodetachment spectroscopy over 20 min of ion storage. In equilibrium with the low-level blackbody field, we find an effective radiative temperature near 15 K with about 90% of all ions in the rotational ground state. We measure the J=1 natural lifetime (about 193 s) and determine the OH^{-} rotational transition dipole moment with 1.5% uncertainty. We also measure rotationally dependent relative near-threshold photodetachment cross sections for photodetachment thermometry.

The cryogenic storage ring CSR.

An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

Photodissociation of an Internally Cold Beam of CH

We have studied the photodissociation of CH^{+} in the Cryogenic Storage Ring at ambient temperatures below 10 K. Owing to the extremely high vacuum of the cryogenic environment, we were able to store CH^{+} beams with a kinetic energy of ∼60 keV for several minutes. Using a pulsed laser, we observed Feshbach-type near-threshold photodissociation resonances for the rotational levels J=0-2 of CH^{+}, exclusively. In comparison to updated, state-of-the-art calculations, we find excellent agreement in the relative intensities of the resonances for a given J, and we can extract time-dependent level populations. Thus, we can monitor the spontaneous relaxation of CH^{+} to its lowest rotational states and demonstrate the preparation of an internally cold beam of molecular ions.

A serial echocardiographic study of myocardial abscess in a patient surviving staphylococcal septicemia.

2D echocardiography was performed on a 4-year-old child suffering from right thigh abscess due to MRSA infection following diagnosis of pericardial effusion by USG abdomen. It revealed myocardial abscess and pericardial effusion. This child underwent series of 2D echocardiographic studies which showed image appearance of myocardial abscess with its time course of healing.

Cα-Cß chromophore bond dissociation in protonated tyrosine-methionine, methionine-tyrosine, tryptophan-methionine, methionine-tryptophan and their sulfoxide analogs.

C(α)-C(ß) chromophore bond dissociation in some selected methionine-containing dipeptides induced by UV photons is investigated. In methionine containing dipeptides with tryptophan as the UV chromophore, the tryptophan side chain is ejected either as an ion or as a neutral fragment while in dipeptides with tyrosine, the tyrosine side chain is lost only as a neutral fragment. Mechanisms responsible for these fragmentations are proposed based on measured branching ratios and fragmentation times, and on the results of DFT/B3-LYP calculations. It appears that the C(α)-C(ß) bond cleavage is a non-statistical dissociation for the peptides containing tyrosine, and occurs after internal conversion for those with tryptophan. The proposed mechanisms are governed by the ionization potential of the aromatic side chain compared to that of the rest of the molecule, and by the proton affinity of the aromatic side chain compared to that of the methionine side chain. In tyrosine-containing peptides, the presence of oxygen on sulfur of methionine presumably reduces the ionization potential of the peptide backbone, facilitating the loss of the side chain as a neutral fragment. In tryptophan-containing peptides, the presence of oxygen on methionyl-sulfur expedites the transfer of the proton from the side chain to the sulfoxide, which facilitates the loss of the neutral side chain.