冰结合蛋白质的尺寸和聚合如何控制它们的冰核效率
Yuqing Qiu1, Arpa Hudait1, Valeria Molinero1
1Department of Chemistry , The University of Utah , 315 South 1400 East , Salt Lake City , Utah 84112-0580 , United States.
Journal of the American Chemical Society
|April 13, 2019
概括
细菌使用冰核蛋白 (INP) 来生存. 这项研究揭示了INP聚合和精确的间距对于有效的冰核形成至关重要,解释了细菌的寒冷适应策略.
科学领域:
- 生物物理
- 材料科学
- 微生物学
背景情况:
- 寒冷环境中的生物利用结冰蛋白来调节冰的形成.
- 细菌的冰核蛋白 (INP) 是膜结合的聚合物,而昆虫的抗蛋白 (AFP) 是可溶和小的.
- 较高的冰核温度与较大的冰结合蛋白和聚合物相关,但缺乏定量理解.
研究的目的:
- 量化确定冰结合蛋白的大小和聚合如何影响冰核化温度 (T_het).
- 将细菌INP与昆虫AFP的冰核化效率进行比较.
- 使用核化理论预测细菌INP聚合物的T_het.
主要方法:
- 用分子模拟来研究抗蛋白TmAFP的冰核化.
- 古典核化理论被用来确定有限大小的表面的T_het.
- 该理论模型与模拟结果进行了验证,然后用于预测细菌INP聚合物的T_het.
主要成果:
- 防蛋白TmAFP在同质核化温度以上2±1°C时核化冰.
- 在TmAFP中添加结冰环可增加T_het,但不能与细菌INP的效率相匹配.
- 34种蛋白质的细菌INP聚合物达到2°C的特征T.
- 在聚合物中表现出非单调的依赖INP之间的距离.
结论:
- 蛋白质的大小和聚合有很大影响冰核化温度.
- 细菌需要精确地控制膜中的INP间距,以获得最佳的冷效率.
- 这项研究为了解蛋白质组合的冰核提供了定量框架.
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