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Crystal Protein (crystal + protein)

Distribution by Scientific Domains
Life Sciences50%

Selected Abstracts

A new group of parasporal inclusions encoded by the S-layer gene of Bacillus thuringiensis

FEMS MICROBIOLOGY LETTERS, Issue 1 2008
Gang Guo
Abstract Bacillus thuringiensis produces various groups of active proteins, such as Cyt, Vip and Parasporin, in addition to the Cry protein. In this study we show S-layer proteins to be a new group of parasporal inclusions of B. thuringiensis. The S-layer consists of a two-dimensional lattice structure and is the outermost component of many archaeobacteria and eubacteria. The parasporal inclusion of B. thuringiensis strain CTC was found to be not a typical crystal protein encoded by the cry gene, but a proteinaceous inclusion encoded by the S-layer gene. Furthermore, the CTC-like strains (with their parasporal inclusions coded by the S-layer gene) are widely distributed and accounted for 25.4% of the B. thuringiensis strains tested. These strains constitue a new group of parasporal inclusions encoded by the S-layer gene of B. thuringiensis and shed new light on B. thuringiensis nontoxic strains. [source]

Crystallization of parasporin-2, a Bacillus thuringiensis crystal protein with selective cytocidal activity against human cells

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 12-2 2004
Toshihiko Akiba
Bacillus thuringiensis is a valuable source of protein toxins that are specifically effective against certain insects and worms but harmless to mammals. In contrast, a protein toxin obtained from B. thuringiensis strain A1547, designated parasporin-2, is not insecticidal but has a strong cytocidal activity against human cells with markedly divergent target specificity. The 37,kDa inactive protein is proteolytically activated to a 30,kDa active form. The active form of the recombinant protein toxin was crystallized in the presence of ethylene glycol and polyethylene glycol 8000 at neutral pH. The crystals belong to the hexagonal space group P61 or P65, with unit-cell parameters a = b = 134.37, c = 121.24,Å. Diffraction data from a native crystal were collected to 2.75,Å resolution using a synchrotron-radiation source. [source]

Susceptibility of the pine processionary caterpillar Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) toward ,-endotoxins of Bacillus thuringiensis under laboratory conditions

ANNALS OF APPLIED BIOLOGY, Issue 3 2001
A B SHEVELEV
Summary A series of natural crystal proteins from B. thuringiensis subsp. Alesti 12,25, caucasicus, galleriae 11,67, galleriae 6,96, kenyae, and shondungensis and spore-crystal preparations from finitimus 11,66 and from a recombinant strain of B. thuringiensis subsp. kurstaki expressing Cry 1 Ga1 only, were assessed as a toxic agent for the pine processionary caterpillar, Thaumetopoea pityocampa. Some preparations had a thoroughly investigated composition and contained Cry1Aa, Cry1Ab2, Cry1Ab7, Cry1D, Cry1F, Cry 1 Ga1, Cry9Aa, Cry26 crystal proteins, whereas crystals of B. thuringiensis subsp. caucasicus, kenyae, and shondungensis harboured predominantly unidentified toxins distant from commonly used prototypes. Bioassays were based on the simultaneous assignment of each treatment to groups of 20 full sibling first-instar larvae, obtained from broods of a population from North-western Italy. The toxin was applied to pine needles by the leaf dipping method and the effect was registered in both feeding inhibition and mortality. B. thuringiensis subsp. caucasicus, kenyae, galleriae 6,96, alesti, and galleriae 11,67 gave the best results in terms of both feeding inhibition and larval mortality. Broods tested in B. thuringiensis bioassays showed a substantial variation in susceptibility to the toxins, suggesting the potential development of resistance in the population. [source]

Proteins specifically hyperexpressed in a coeliac disease patient with aberrant T cells

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2007
V. De Re
Summary An aberrant T cell population is the basis for diagnosis of refractory coeliac disease and determines the risk of enteropathy-associated T cell lymphoma. This disease is serious with a poor survival. Pathogenetic mechanisms sustaining aberrant T cell proliferation remain unknown. Recently, alemtuzumab has been proposed as a promising new approach to treat these patients. Only few single cases have been tested at present; nevertheless, in all the cases a clinical improvement was observed. However, whether intraepithelial lymphocytes have been targeted effectively by alemtuzumab is still debated. This study reports, using two-dimensional difference gel electrophoresis (2D DIGE), hyperexpressed proteins associated specifically with aberrant T cells found in a patient with coeliac disease by comparison of the protein expression of this sample with that of patients with coeliac disease and polyclonal T cells or with control subjects. The data demonstrated a significantly higher expression of IgM, apolipoprotein C-III and Charcot,Leyden crystal proteins in a duodenal biopsy specimen of the patient with clonal T cells compared with that of other patients. These preliminary results allow hypothesizing different clinical effects of alemtuzumab in patients with coeliac disease and aberrant T cell proliferation, because as well as the probable effect on T cells, alemtuzumab could exert its effect by acting on inflammatory associated CD52+ IgM+ B cells and eosinophil cells, known to produce IgM and Charcot,Leyden crystal proteins, that we demonstrated to be altered in this patient. The results also emphasize the possible association of apolipoprotein with aberrant T cell proliferation. [source]