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几种因子对离体豌豆叶绿体蛋白质合成的影响

摘要

豌豆叶绿体蛋白质合成的饱和光强为450#mu#mol m~(-2) s~(-1),合成的速率在最初5min内最大,此后随时间延长而合成速率下降;K~(+)对蛋白质合成有促进作用,Mg~(2+)在1mmol/L以下对蛋白质合成有轻微的促进作用;叶绿体的蛋白质合成随着外源氨基酸浓度的增加而很快地增加,但超过220#mu#mol/L以后蛋白质合成随浓度增加而有所降低。DCMU抑制叶绿体蛋白质的合成。荧光自显影结果表明,叶绿体合成的主要间质蛋白为Rubisco大亚基,合成的类囊体膜蛋白中以32kD较为明显。

关键词： 完整叶绿体; 光照; 蛋白质合成

Effects of some factors on protein synthesis in isolated chloroplast

Abstract

The protein synthesis by isolated chloroplasts was light-driven and the saturation light intensity was 450 #mu#mol m~(-2) s~(-1). The rate of protein synthesis was at its maximum in the initial 5 min of illumination and then declined gradually. K~(+) stimulated protein synthesis in isolated chloroplasts, but the stimulation decreased when the concentration of K~(+) was above 30-40 mmol/L. Mg~(2+) stimulated slightly protein synthesis up to a concentration of 1 mmol/L, then the stimulation decreased and obvious inhibition occurred when its concentration was higher than 1.5 mmol/L. The amino acids stimulated effectively protein synthesis in isolated chloroplasts, but stimulation decreased when the concentration of amino acids was above 200 #mu#mol/L. Protein synthesis in isolated chloroplasts was inhibited by DCMU, an inhibitor of noncyclic photophosphorylation, by as much as 41% of the control, indicating the magnitude of the role of noncyclic photophosphorylation in providing ATP for protein synthesis. SDS-PAGE and fluorography showed that the major stromal protein synthesized by isolated chloroplasts was the large subunit of Rubisco, the 32 kD protein in thylakoid membrane was also labeled distinctly.

Key words: Intact chloroplast;Illumination;Protein synthesis

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引用本文：

. 几种因子对离体豌豆叶绿体蛋白质合成的影响[J]. 生理学报 1998; 50 (1): .

. Effects of some factors on protein synthesis in isolated chloroplast. Acta Physiol Sin 1998; 50 (1): (in Chinese with English abstract).