Zhang Tuodi, Deng Xudong, Zhao Fengzhu, Shi Wenpu, Chen Liangliang, Zhou Yaqing, Wang Xueting, Zhang Chenyan, Yin Dachuan
Key Laboratory for Space Bioscience & Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, China.
Sheng Wu Gong Cheng Xue Bao. 2021 Apr 25;37(4):1396-1405. doi: 10.13345/j.cjb.200486.
Protein self-assemblies at the micro- and nano-scale are of great interest because of their morphological diversity and good biocompatibility. High-throughput screening of protein self-assembly at different scales and morphologies using protein crystallization screening conditions is an emerging method. When using this method to screen protein self-assembly conditions, some apparently transparent droplets are often observed, in which it is not clear whether self-assembly occurs. We explored the interaction between β-lactoglobulin and the protein crystallization kit Index™ C10 and observed the presence of micro- and nano-scale protein self-assemblies in the transparent droplets. The diverse morphology of the micro- and nano-scale self-assemblies in the transparent droplets formed by mixing different initial concentrations of β-lactoglobulin and Index™ C10 was further investigated by scanning electron microscope. Self-assembly process of fluorescence-labelled β-lactoglobulin was monitored continuously by laser confocal microscope, allowing real-time observation of the liquid-liquid phase separation phenomenon and the morphology of the final self-assemblies. The internal structure of the self-assemblies was gradually ordered over time by in-situ X-ray diffraction. This indicates that the self-assembly phenomenon within transparent droplets, observed in protein self-assembly condition screening experiments, is worthy of further in-depth exploration.
由于其形态多样性和良好的生物相容性，微米和纳米尺度的蛋白质自组装备受关注。利用蛋白质结晶筛选条件对不同尺度和形态的蛋白质自组装进行高通量筛选是一种新兴方法。使用该方法筛选蛋白质自组装条件时，经常会观察到一些看似透明的液滴，其中是否发生自组装并不明确。我们研究了β-乳球蛋白与蛋白质结晶试剂盒Index™ C10之间的相互作用，并在透明液滴中观察到了微米和纳米尺度的蛋白质自组装。通过扫描电子显微镜进一步研究了由不同初始浓度的β-乳球蛋白和Index™ C10混合形成的透明液滴中微米和纳米尺度自组装的多样形态。通过激光共聚焦显微镜连续监测荧光标记的β-乳球蛋白的自组装过程，从而实时观察液-液相分离现象和最终自组装体的形态。通过原位X射线衍射，自组装体的内部结构随时间逐渐有序化。这表明在蛋白质自组装条件筛选实验中观察到的透明液滴内的自组装现象值得进一步深入探索。
