scholarly journals TrypanothioneS-Transferase Activity in a Trypanosomatid Ribosomal Elongation Factor 1B

2004 ◽  
Vol 279 (26) ◽  
pp. 27246-27256 ◽  
Author(s):  
Tim J. Vickers ◽  
Alan H. Fairlamb
2013 ◽  
Vol 59 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Nerino Allocati ◽  
Michele Masulli ◽  
Piero Del Boccio ◽  
Damiana Pieragostino ◽  
Domenico D’Antonio ◽  
...  

2006 ◽  
Vol 11 (7) ◽  
pp. 736-742 ◽  
Author(s):  
Steven Swaney ◽  
Mark McCroskey ◽  
Dean Shinabarger ◽  
Zhigang Wang ◽  
Benjamin A. Turner ◽  
...  

Elongation Factor P (EF-P) is an essential component of bacterial protein synthesis, enhancing the rate of translation by facilitating the addition of amino acids to the growing peptide chain. Using purified Staphylococcus aureus EF-P and a reconstituted Escherichia coli ribosomal system, an assay monitoring the addition of radiolabeled N-formyl methionine to biotinylated puromycin was developed. Reaction products were captured with streptavidin-coated scintillation proximity assay (SPA) beads and quantified by scintillation counting. Data from the assay were used to create a kinetic model of the reaction scheme. In this model, EF-P binding to the ribosome essentially doubled the rate of the ribosomal peptidyl transferase reaction. As described here, EF-P bound to the ribosomes with an apparent Ka of 0.75 μM, and the substrates N-fMet-tRNA and biotinylated puromycin had apparent Kms of 19 μM and 0.5 μM, respectively. The assay was shown to be sensitive to a number of antibiotics known to target ribosomal peptide bond synthesis, such as chloramphenicol and puromycin, but not inhibitors that target other stages of protein synthesis, such as fusidic acid or thiostrepton.


2018 ◽  
Vol 2 (1) ◽  
pp. 49
Author(s):  
Enis Uruci

Exposure prevention is the primary strategy to reduce the risk of occupational bloodborne pathogen infections in healthcare workers (HCW). HCWs should be made aware of the medicolegal and clinical relevance of reporting an exposure, and have ready access to expert consultants to receive appropriate counselling, treatment and follow-up. Vaccination against hepatitis B virus (HBV), and demonstration of immunisation before employment are strongly recommended. HCWs with postvaccinal anti-HBs levels, 1-2 months after vaccine completion, .or=10 mIU/mL are considered as responders. Responders are protected against HBV infection: booster doses of vaccine or periodic antibody concentration testing are not recommended. Alternative strategies to overcome non-response should be adopted. Isolated anti-HBc positive HCWs should be tested for anti-HBcIgM and HBV-DNA: if negative, anti-HBs response to vaccination can distinguish between infection (anti-HBs .or=50 mIU/ml 30 days after 1st vaccination: anamnestic response) and false positive results(anti-HBs .or=10 mUI/ml 30 days after 3rd vaccination: primary response); true positive subjects have resistance to re-infection. and do not need vaccination The management of an occupational exposure to HBV differs according to the susceptibility of the exposed HCW and the serostatus of the source. When indicated, post-exposure prophylaxis with HBV vaccine, hepatitis B immunoglobulin or both must be started as soon as possible (within 1-7 days). In the absence of prophylaxis against hepatitis C virus (HCV) infection, follow-up management of HCV exposures depends on whether antiviral treatment during the acute phase is chosen. Test the HCW for HCV-Ab at baseline and after 6 months; up to 12 for HIV-HCV co-infected sources. If treatment is recommended, perform ALT (amino alanine transferase) activity at baseline and monthly for 4 months after exposure, and qualitative HCV-RNA when an increase is detected. Introduction Bloodborne pathogens such as hepatitis B (HBV) and C virus (HCV) represent an important hazard for healthcare workers (HCWs) (1). In the general population, HCV prevalence varies geographically from about 0.5% in northern countries to 2% in Mediterranean countries, with some 5 million chronic carriers estimated in Europe; while HBV prevalence ranges from 0.3% to 3%. The World Health Organization (WHO) estimates that each year in Europe 304 000 HCWs are exposed to at least one percutaneous injury with a sharp object contaminated with HBV, 149 000 are exposed to HCV and 22 000 to HIV. The probability of acquiring a bloodborne infection following an occupational exposure has been estimated to be on average.


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