Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
Biomaterials. 2011 Aug;32(23):5311-9. doi: 10.1016/j.biomaterials.2011.04.027. Epub 2011 May 7.
A synthetic peptide derived from the native protein sequence of a metal binding bacterial pilus was observed to spontaneously react with stainless steel via a previously unreported type of chemical interaction to generate an altered form of stainless steel which we term bioorganic stainless steel. Bioorganic stainless steel has a significantly increased electron work function (4.9 ± 0.05 eV compared to 4.79 ± 0.07 eV), decreased material adhesive force (19.4 ± 8.8 nN compared to 56.7 ± 10.5 nN), and is significantly harder than regular 304 stainless steel (~40% harder). A formal or semi-formal organo-metallic covalent bond is generated between a pilin receptor binding domain and stainless steel based on XPS analysis which indicates that the electronic state of the surface is altered. Further, we establish that the peptide-steel reaction demonstrates a degree of stereospecificity as the reaction of native L-peptide, D-peptide and a retro-inverso-D-peptide yields bioorganic steel products that can be differentiated via the resulting EWF (4.867 ± 0.008 eV, 4.651 ± 0.008 eV, and 4.919 ± 0.007 eV, respectively). We conclude that electron sharing between the peptide and steel surface results in the stabilization of surface electrons to generate bioorganic steel that displays altered properties relative to the initial starting material. The bioorganic steel generated from the retro-inverso-D-peptide yields a protease stable product that is harder (41% harder at a 400 μN load), and has a 50% lower corrosion rate compared with regular stainless steel (0.11 ± 0.03 mpy and 0.22 ± 0.04 mpy, respectively). Bioorganic steel is readily fabricated.
一种合成肽源自天然金属结合菌毛的蛋白质序列，通过一种以前未报道过的化学相互作用与不锈钢自发反应，生成一种我们称之为生物有机不锈钢的不锈钢的变体。生物有机不锈钢的电子功函数显著增加（4.9±0.05eV 相比 4.79±0.07eV），材料粘附力降低（19.4±8.8nN 相比 56.7±10.5nN），并且比普通 304 不锈钢硬得多（约硬 40%）。基于 XPS 分析，在 Pilin 受体结合域和不锈钢之间生成了正式或半正式的有机金属共价键，表明表面的电子状态发生了改变。此外，我们还确定了肽-钢反应具有一定的立体特异性，因为天然 L-肽、D-肽和反式 D-肽的反应生成了可通过产生的 EWF（4.867±0.008eV、4.651±0.008eV 和 4.919±0.007eV 分别）区分的生物有机钢产物。我们得出结论，肽和钢表面之间的电子共享导致表面电子的稳定化，从而生成显示相对于初始起始材料改变的性质的生物有机钢。由反式 D-肽生成的生物有机钢生成了一种蛋白酶稳定的产物，其硬度提高了 41%（在 400μN 负载下），并且与普通不锈钢相比，腐蚀率降低了 50%（分别为 0.11±0.03mpy 和 0.22±0.04mpy）。生物有机钢易于制造。
