| 1. |
- Novak, R, et al.
(författare)
-
Extracellular targeting of choline-binding proteins in Streptococcus pneumoniae by a zinc metalloprotease.
- 2000
-
Ingår i: Molecular Microbiology. - 0950-382X .- 1365-2958. ; 36:2, s. 366-376
-
Tidskriftsartikel (refereegranskat)abstract
- A genetic-based search for surface proteins of Streptococcus pneumoniae involved in adhesion identified a putative zinc metalloprotease (ZmpB). ZmpB shared high amino acid sequence similarities with IgA1 proteases of Gram-positive bacteria, but ZmpB had neither IgA1 nor IgA2 protease activity. Analysis of a family of surface-expressed proteins, the choline-binding proteins (Cbp's), in a zmpB-deficient mutant demonstrated a global loss of surface expression of CbpA, CbpE, CbpF and CbpJ. CbpA was detected within the cytoplasm. The zmpB-deficient mutant also failed to lyse with penicillin, a sign of lack of function of the Cbp LytA. Immunodetection studies revealed that the autolysin (LytA), normally located on the cell wall, was trapped in the cytoplasm colocalized with DNA and the transformation protein CinA. Trafficking of CinA and RecA to the cell membrane during genetic competence was also not observed in the zmpB-deficient mutant. These results suggest a protease dependent regulatory mechanism governing the translocation of CinA and the Cbp's LytA and CbpA of S. pneumoniae.
|
|
| 2. |
|
|
| 3. |
- Hegyesi, G., et al.
(författare)
-
Development of an FPGA-based data acquisition module for small animal PET
- 2004
-
Ingår i: 2004 IEEE Nuclear Science Symposium Conference Record. - 0780387007 ; , s. 2957-2961
-
Konferensbidrag (refereegranskat)abstract
- We report on the design of a DAQ module for a small animal PET camera developed at our institutes. During the design an important guideline was to develop a system which is built up from strictly identical DAQ modules, and which has no built-in hardware limitation on the maximum number of modules. The developed DAQ module comprises of an LSO scintillator crystal block, a position sensitive PMT, analog signal conditioning circuits, a digitizer, an FPGA for digital signal processing and a communication module through which the collected data is sent to a cluster of computers for post processing and storage. Instead of implementing hardware coincidence detection between the modules we attach a precise time-stamp to each event in our design, and the coincidence is determined by the data collecting computers during the post processing. The digital CFD algorithm implemented in the FPGA gives a time resolution of 2 to 3 ns FWHM for real detector signals.
|
|
| 4. |
|
|
| 5. |
- Novak, R, et al.
(författare)
-
Signal transduction by a death signal peptide : uncovering the mechanism of bacterial killing by penicillin.
- 2000
-
Ingår i: Molecular Cell. - 1097-2765 .- 1097-4164. ; 5:1, s. 49-57
-
Tidskriftsartikel (refereegranskat)abstract
- The binding of bactericidal antibiotics like penicillins, cephalosporins, and glycopeptides to their bacterial targets stops bacterial growth but does not directly cause cell death. A second process arising from the bacteria itself is necessary to trigger endogenous suicidal enzymes that dissolve the cell wall during autolysis. The signal and the trigger pathway for this event are completely unknown. Using S. pneumoniae as a model, we demonstrate that signal transduction via the two-component system VncR/S triggers multiple death pathways. We show that the signal sensed by VncR/S is a secreted peptide, Pep27, that initiates the cell death program. These data depict a novel model for the control of bacterial cell death.
|
|
| 6. |
- Szolnoky, G, et al.
(författare)
-
A mannose-binding receptor is expressed on human keratinocytes and mediates killing of Candida albicans.
- 2001
-
Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 117:2, s. 205-13
-
Tidskriftsartikel (refereegranskat)abstract
- Human keratinocytes are known to kill Candida albicans in vitro, but the mechanism of killing is not yet understood. Here, we demonstrate that spontaneous, ultraviolet-B-light-induced, alpha-melanocyte-stimulating-hormone-induced, and interleukin-8-induced Candida killing by keratinocytes can be inhibited with mannan and mannosylated bovine serum albumin (Man-BSA). A polyclonal goat serum raised against the human macrophage mannose receptor stained suprabasal keratinocytes, but no staining was observed on keratinocytes with a monoclonal antibody (mAb15) specific for the human macrophage mannose receptor. Mannose-affinity chromatography of keratinocyte extract isolated a 200 kDa protein, and on the Western blot the goat antiserum reacted with a 200 kDa protein. In radioligand binding studies, the binding of 125I-Man-BSA to human keratinocytes was inhibited by mannan in a concentration-dependent manner. Analysis of the binding revealed a single class keratinocyte mannose receptor with a KD of 1.4 x 10(-8) M and a Bmax of 1 x 10(4) binding sites per cell. The binding of 125I-Man- BSA to keratinocytes proved to be time-dependent, acid-precipitable, and Ca2+- and trypsin-sensitive. After trypsinization the receptors underwent a rapid recovery at 37 degrees C. These results demonstrate the presence of mannose receptor on human keratinocytes, and its active involvement in the killing of Candida albicans.
|
|
| 7. |
- Westman, S., et al.
(författare)
-
Heavy ion detection at extreme high vacuum by means of a YAP : Ce scintillator
- 2002
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - 0168-9002 .- 1872-9576. ; 481:1-3, s. 655-660
-
Tidskriftsartikel (refereegranskat)abstract
- A device for the detection of highly charged heavy ions in the CRYRING accelerator is presented. The system consists of a YAP: Ce scintillator, including a set of reflectors and lenses for the transmission of the scintillation light to the PM-tube. The performance of the system has been tested in measurements with electron cooled heavy ion beams.
|
|
