Incorporation of norvaline at leucine positions in recombinant human hemoglobin expressed in Escherichia coli
Incorporation of norvaline at leucine positions in recombinant human hemoglobin expressed in Escherichia coli
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DOI：
10.1074/jbc.272.46.28980
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发表时间：
1997-11-14
影响因子：
4.8
通讯作者：
Blackmore, R
中科院分区：
文献类型：
--
作者：
Apostol, I;Levine, J;Blackmore, R
我们在此报道了一个新的发现，即正缬氨酸可以取代亮氨酸掺入大肠杆菌表达的重组人血红蛋白中。正缬氨酸的存在通过几种分析方法如氨基酸分析、肽图谱、电喷雾质谱和Edman蛋白测序来证实。看来，在纯化的重组血红蛋白中，正缬氨酸的取代分布在β-和二-α-球蛋白中，这表明正缬氨酸与亮氨酸的掺入是通过tRNA（Leu）的氨基酰化错误发生的，类似于在大肠杆菌中表达的许多重组蛋白中发现的正亮氨酸与甲硫氨酸的误掺入。杆菌
We report here a novel finding that norvaline can be incorporated in place of leucine in recombinant human hemoglobin expressed in Escherichia coli, The presence of the norvaline was confirmed by several analytical methods such as amino acid analysis, peptide mapping, electrospray mass spectrometry, and Edman protein sequencing, It appears that substitution is distributed across both the beta- and di-alpha-globins in purified recombinant hemoglobin, The level of misincorporation correlated with the ratio of the free norvaline/leucine pool available in the cell culture, This suggests that the incorporation of norvaline for leucine occurs through misaminoacylation of tRNA(Leu), similar to the misincorporation of norleucine for methionine found in many recombinant proteins expressed in E. coli.