Direct 13C detection
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... Determining organic structures 43 -- Introduction 43 -- Mass spectrometry 46 -- Mass spectrometry detects ... ... determined by high-resolution mass spectrometry 50 -- Nuclear magnetic resonance 52 -- Regions of the 13C ... ... NMR spectrum 56 -- Different ways of describing chemical shift 57 -- A guided tour of the 13C NMR spectra ... ... Sigmatropic rearrangements 909 -- Orbital descriptions of [3,31-sigmatropic rearrangements 912 -- The direction ... ... 1041 -- Other kinetic evidence for reaction mechanisms 1050 -- Acid and base catalysis 1053 -- The detection ...
Second edition xxv, 1234 stran : ilustrace ; 28 cm
- Konspekt
- Organická chemie
- NLK Obory
- chemie, klinická chemie
- NLK Publikační typ
- učebnice vysokých škol
Two novel 5D NMR experiments (CACONCACO, NCOCANCO) for backbone assignment of disordered proteins are presented. The pulse sequences exploit relaxation properties of the unstructured proteins and combine the advantages of (13)C-direct detection, non-uniform sampling, and longitudinal relaxation optimization to maximize the achievable resolution and minimize the experimental time. The pulse sequences were successfully tested on the sample of partially disordered delta subunit from RNA polymerase from Bacillus subtilis. The unstructured part of this 20 kDa protein consists of 81 amino acids with frequent sequential repeats. A collection of 0.0003% of the data needed for a conventional experiment with linear sampling was sufficient to perform an unambiguous assignment of the disordered part of the protein from a single 5D spectrum.
- MeSH
- Bacillus subtilis enzymologie MeSH
- bakteriální proteiny chemie MeSH
- DNA řízené RNA-polymerasy chemie MeSH
- izotopy uhlíku MeSH
- konformace proteinů MeSH
- nukleární magnetická rezonance biomolekulární metody MeSH
- proteiny chemie MeSH
- sekvence aminokyselin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
One of the challenges the microbial ecologists are facing is the identification of microorganisms that are responsible for particular biochemical processes in the environment. Although small- subunit rRNA gene sequencing is a robust technique whereby the phylogenetic diversity of microbial communities can be described, it provides few direct links between the identity of microorganisms and their metabolic capabilities and function in the environment. In contrast, when a microorganism is cultivable, it can be identified, after isolation, and characterized at the physiological, biochemical and genetic level. However, only a small fraction of microorganisms present in the environment have been successfully cultivated. Stable isotope probing (SIP) techniques are based on analyzing biomarkers (nucleic acids or phospholipid-derived fatty acids) after microbial consumption of 13C- or 15N-labelled substrate added to an environmental sample. The use of SIP allows the direct detection of microorganisms that are truly active in the degradation and assimilation of a particular substrate within a complex microbial community. The main advantages of this method are its cultivation independence and the fact that it links the identity of microorganisms with their function in the environment.
