They provide a turnover frequency of TOF = 6.2 and 6.4 min−1 for the hydrolysis of SB and AB at 25.0 ± 0.5 °C, respectively.
Finally, by comparing the ATP-ADP steady-state exchange rate to the amount of the ANT in rat brain synaptic, brain nonsynaptic, heart and liver mitochondria, we provide molecular turnover numbers for the known ANT isotypes.
Polymethylhydrosiloxane and triphenylsilane did not provide catalytic turnover (Table 1, entries 3 and 4).
This is firstly owing to the frequent sampling per individual during labeling and delabeling phases, and secondly because in long-term labeling studies the information on cell turnover is recorded over a period of several weeks, thereby providing a turnover estimate that is considerably less sensitive to fluctuations in cell turnover than, for example, a 'snapshot' measurement of Ki-67 expression.
Markers of bone turnover provide an integrated measure of systemic turnover, and several studies have demonstrated significant elevations in, especially, resorption markers in RA [ 17- 20].
In vitro phosphorylation assays providing multiple turnover conditions were performed in a final volume of 25 µl of reaction buffer (50 mM Tris-HCl, pH 7.5, 50 mM KCl, 10 mM MgCl2, 0.5 mM ATP, 420 nM [γ33P]ATP (3000 Ci/mmol)).
In turn, fully differentiated blood cells (not all shown in Fig. 3) are cleared from the peripheral pool at rate μd, providing a turnover mechanism.
An increase in protein degradation during starvation allows the cell to survive stressful conditions by providing nutrient turnover when extracellular nutrients are scarce.
It has been suggested that resistance of cells to environmental stress factors, including starvation, vastly depends on their ability to activate compensatory reactions, providing rapid turnover of damaged molecules and entire organelles such as mitochondria.
Biochemical markers of bone turnover provide important indications for the early diagnosis of osteoporosis and reflect bone formation and resorption through the bone turnover rate [ 19].
