Western blot analysis of the protein extract of naive PC12 cell and differentiated PC12 cell using anti 6-nitrotryptophan antibody showed several immunoreactive bands, which were subsequently subjected to trypsin digestion and LC-ESI-MS-MS analysis. The peptides from five ribosomal proteins, namely, 60S ribosomal protein 17 (Trp154), 60S acidic ribosomal protein PI (Trp43), 405 ribosomal protein S2 (Trp60), 405 ribosomal protein S6 (Trp45), and 40S ribosomal protein S19 (Trp52), were identified click here as nitrotryptophan residue-containing proteins with significant ion score levels (p < 0.05). Among these, tryptophan nitration was observed only in differentiated PC12 cell for S19 protein,
and only in naive PCl2 cell for L7 protein. Tryptophan nitration of the other ribosomal proteins P1, S2, and S6 was observed in both naive and differentiated PC12 cells.
The positive signal of nitrotryptophan-containing proteins in the Western blotting around 16 kDa (Band 1), which includes 40S ribosomal protein S19, was suppressed by treatment with NOS inhibitor, L-NAME. The tryptophan nitration of 40S ribosomal Selleck Tozasertib protein was not observed by LC-ESI-MS-MS
analysis of this sample.
This is the first study to identify several specific sites of nitrated tryptophan on proteins not only in viable culture cells but also in a physiological process: cell differentiation. (C) 2011 Elsevier Inc. All rights reserved.”
“Dynamics of growth and decline of microbial populations were analysed and respective models were developed in this investigation. Analysis of the dynamics was based check on general considerations concerning the main properties of microorganisms and their interactions with the environment which was supposed to be affected by the activity of the population. Those considerations were expressed mathematically by differential
equations or systems of the equations containing minimal sets of parameters characterizing those properties. It has been found that: (1) the factors leading to the decline of the population have to be considered separately, namely, accumulation of metabolites (toxins) in the medium and the exhaustion of resources; the latter have to be separated again into renewable (‘building materials’) and non-renewable (sources of energy); (2) decline of the population is caused by the exhaustion of sources of energy but no decline is predicted by the model because of the exhaustion of renewable resources; (3) the model determined by the accumulation of metabolites (toxins) in the medium does not suggest the existence of a separate ‘stationary phase’; (4) in the model determined by the exhaustion of energy resources the ‘stationary’ and ‘decline’ phases are quite discernible; and (5) there is no symmetry in microbial population dynamics, the decline being slower than the rise.