Evidence for pro-β-nerve growth factor, a biosynthetic precursor to β-nerve growth factor
Evidence for pro-β-nerve growth factor, a biosynthetic precursor to β-nerve growth factor
复制标题
β-神经生长因子前体（β-神经生长因子的生物合成前体）的证据
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
E. Shooter
中科院分区：
文献类型：
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作者：
E. Berger;E. Shooter
摘要
用L-[~（35）S]胱氨酸孵育小鼠颌下腺，研究β-神经生长因子（β-NGF）的生物合成。通过加入抗βNGF的抗血清从组织提取物中分离βNGF，洗涤的免疫沉淀物通过十二烷基硫酸钠凝胶电泳分析。标记时间较短（10和25 min），主要标记物质的表观分子量为22，000，较小的峰与纯化的βNGF链共迁移（13，260）。随着时间的推移，22，000分子量峰中的放射性趋于稳定，而βNGF中的标记物继续增加，直到4小时时其大大超过22，000分子量物质的放射性。当将孵育10分钟的腺体转移到含有大量过量未标记L-胱氨酸的培养基中时，22，000分子量峰逐渐下降，βNGF位置的放射性相应增加。从十二烷基硫酸钠凝胶中分离的22，000分子量的物质具有βNGF的所有含胱氨酸肽，可能还有两个额外的肽。将标记25 min的颌下腺免疫沉淀物与γ亚基（一种与7S NGF复合物中βNGF相关的特异性乙酰酯肽酶）孵育时，22，000分子量物质中的放射性转化为βNGF位置。结果表明，22，000分子量的种类是βNGF的生物合成前体，并且γ亚基可能在加工事件中起特异性蛋白酶的作用。
Abstract
The biosynthesis of β-nerve growth factor (βNGF) was studied in mouse submaxillary glands incubated with L-[35S]cystine. βNGF was isolated from tissue extracts by the addition of antiserum against βNGF and the washed immunoprecipitates were analyzed by sodium dodecyl sulfate gel electrophoresis. With short labeling periods (10 and 25 min) there is a major labeled species with an apparent molecular weight of 22,000 and a smaller peak comigrating with purified βNGF chains (13,260). As time proceeds, the radioactivity in the 22,000 molecular weight peak plateaus, while the label in βNGF continues to increase, until by 4 hr it greatly exceeds the radioactivity of the 22,000 molecular weight species. When glands incubated for 10 min are transferred to medium containing a large excess of unlabeled L-cystine, the 22,000 molecular weight peak gradually declines, and there is a corresponding increase in radioactivity at the βNGF position. The 22,000 molecular weight species isolated from sodium dodecyl sulfate gels possesses all the cystine-containing peptides of βNGF, and possibly two additional ones. When immunoprecipitates from submaxillary glands labeled for 25 min are incubated with the γ subunit (a specific arginyl-esteropeptidase associated with βNGF in the 7S NGF complex), the radioactivity in the 22,000 molecular weight species is converted to the βNGF position. The results suggest that the 22,000 molecular weight species is a biosynthetic precursor to βNGF, and that the γ subunit may function as a specific protease in the processing event.