Question

List three out of the seven processes that affect the steady-state concentration of a protein and an example of each process (6pts)

Process:                                               Example

1.                                                         

Answer 1

Processes that affect steady -state concentration of a protein with examples are discussed below:-

The term steady - state refers to the concentration of drug in the systemic circulation when the rate of drug elimination is equal to the rate of drug administration. For example, the abundance of a protein might not vary during the time of observation because rates of translation and degradation are balanced. The cell is said to be at steady -state with respect to the concentration of proteins.

Shotgun proteomics experiments can be made quantitative, for example- by measuring ion intensities in the mass spectrometer or by counting spectra they are derived from each peptide. Both techniques enable the absolute quantification of proteins in the sample, providing that the resulting intensities or counts are suitably calibrated to molecular concentrations.

In the automation of microscopy , for example- of the generation of libraries of modified yeast or human cells that express proteins fused to fluorescent proteins or to other detectable epitopes. Such strains provide a direct readout of protein abundance and have led to large scale surveys of protein expression within single cells and cell populations. Perhaps most importantly, the comparison of steady -state concentration data collected from different technologies provided at valuable opportunity of cross-validation. In case of protein abundances, such comparisons have broadly confirmed results from each approach, whereas analyses of protein degradation rates .

Pointing to extremely strong transcriptional or post-tranacriptional regulation, for example- RNAs and proteins from mammalian metabolic genes tend to be very stable and have high proteinper -mRNA ratios, by contrast, proteins that are involved in chromatin organization and transcriptional regulation tend to be rapidly degraded. In addition to steady-state measurement , efforts have now also turned to perturbed systems. To characterize dymnamic changes in proteomes, time-dependent measurements are necessary. The factors affecting the average steady-state concentration are rate of dose administration, which affects proportionally the steady-state plasma concentrations. Bioavailability, which modulates rate of dose administration. After saturation, the relationship between the administered dose and the steady-state plasma concentrations is unpredictable, not following the rule of proportionality. The steady state concentration also be achieved with a series of close up administration to achieve in a very short time the plasma concentrations useful for the therapeutic effect.