Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.
Acta Biomater. 2011 Oct;7(10):3789-95. doi: 10.1016/j.actbio.2011.06.001. Epub 2011 Jun 12.
Honeybees produce silken cocoons containing four related fibrous proteins. High levels of each of the honeybee silk proteins can be produced recombinantly by fermentation in Escherichia coli. In this study we have used electrospinning to fabricate a single recombinant honeybee silk protein, AmelF3, into nanofibers of around 200 nm diameter. Infrared spectroscopy found that the molecular structure of the nanofibers was predominantly coiled coil, essentially the same as native honeybee silk. Mats of the honeybee nanofibers were treated with methanol or by water annealing, which increased their β-sheet content and rendered them water insensitive. The insoluble mats were degraded by protease on a time scale of hours to days. The protease gradually released proteins from the solid state and these were subsequently rapidly degraded into small peptides without the accumulation of partial degradation products. Cell culture assays demonstrated that the mats allowed survival, attachment and proliferation of fibroblasts. These results indicate that honeybee silk proteins meet many prerequisites for use as a biomaterial.
蜜蜂生产的丝茧中含有四种相关的纤维蛋白。通过在大肠杆菌中的发酵，可以重组产生高水平的每种蜜蜂丝蛋白。在这项研究中，我们使用静电纺丝技术将一种重组的蜜蜂丝蛋白 AmelF3 制成了约 200nm 直径的纳米纤维。红外光谱发现，纳米纤维的分子结构主要是卷曲螺旋，与天然蜜蜂丝基本相同。用甲醇或水退火处理的蜜蜂纳米纤维垫，增加了其 β-折叠含量，并使它们对水不敏感。不溶性纤维垫在数小时至数天的时间内被蛋白酶降解。蛋白酶逐渐将蛋白质从固态中释放出来，这些蛋白质随后迅速降解成小肽，而不会积累部分降解产物。细胞培养实验表明，纤维垫允许成纤维细胞存活、附着和增殖。这些结果表明，蜜蜂丝蛋白满足了作为生物材料使用的许多先决条件。
