RESPIRATORY ENERGY-REQUIREMENTS AND RATE OF PROTEIN-TURNOVER IN-VIVO DETERMINED BY THE USE OF AN INHIBITOR OF PROTEIN-SYNTHESIS AND A PROBE TO ASSESS ITS EFFECT
RESPIRATORY ENERGY-REQUIREMENTS AND RATE OF PROTEIN-TURNOVER IN-VIVO DETERMINED BY THE USE OF AN INHIBITOR OF PROTEIN-SYNTHESIS AND A PROBE TO ASSESS ITS EFFECT
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DOI：
10.1111/j.1399-3054.1994.tb03027.x
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发表时间：
1994-12-01
影响因子：
6.4
通讯作者：
LAMBERS, H
中科院分区：
文献类型：
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作者：
BOUMA, TJ;DEVISSER, R;LAMBERS, H
蛋白质周转通常被认为是主要的维持过程，但支持这一论点的实验证据很少。在这里，我们量化了暗呼吸率与体内组织总蛋白质周转相关的成分。在马铃薯（Solanum tuberosum L.）细胞悬浮液上测定了胞浆蛋白合成抑制剂环己亚胺（cycloheximide， CHM）对暗呼吸的影响，并在大豆（Phaseolus vulgaris L.）初生叶和膨大叶的叶盘上定量测定了其对暗呼吸的影响。通过监测对诱导乙烯形成酶（EFE）活性的抑制，评估中药对蛋白质生物合成的体内影响。目前的方法产生了整个蛋白质池的能量成本，而不考虑它们的个别周转率。平均离职率由呼吸成本和离职的特定成本得出。在生长细胞悬浮液和膨大叶片中可以很容易地检测到中草药对呼吸的抑制作用。膨胀叶片中蛋白质周转的呼吸成本最高可达总呼吸的17-37%。大豆成熟初生叶的周转成本占总暗呼吸的17-21%。生长和完全生长叶片的最大降解常数（即k -d值）分别高达2.42 x 10（-6）和1.12 x 10(-6) s（-1）。
Protein turnover is generally regarded as a major maintenance process, but experimental evidence to support this contention is scarce. Here we quantify the component of dark respiration rate associated with overall protein turnover of tissues in vivo. The effect of an inhibitor of cytosolic protein synthesis (cycloheximide, CHM) on dark respiration was tested on a cell suspension from potato (Solanum tuberosum L.) and quantified on leaf discs of expanding and full-grown primary leaves of bean (Phaseolus vulgaris L.). The in vivo effect of CHM on protein biosynthesis was assessed by monitoring the inhibition of the induction of the ethylene-forming enzyme (EFE) activity. The present method yields the energy costs of turnover of the total pool of proteins irrespective of their individual turnover rates. Average turnover rates were derived from the respiratory costs and the specific costs for turnover.Inhibition of respiration by CHM was readily detectable in growing-cell suspensions and discs of expanding leaves. The derived respiratory costs of protein turnover in expanding leaves were maximally 17-37% of total respiration. Turnover costs in full-grown primary leaves of bean amounted to 17-21% of total dark respiration. The maximum degradation constants (i.e. K-d-values) derived for growing and full-grown leaves were up to 2.42 x 10(-6) and 1.12 x 10(-6) s(-1), respectively.