Luijten Jeroen, Groeneveld Daan Y, Nijboer Gerard W, Vorenkamp Eltjo J, Schouten Arend J
Department of Polymer Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Langmuir. 2007 Jul 17;23(15):8163-9. doi: 10.1021/la7005106. Epub 2007 Jun 14.
Using a chemical cross-linking procedure, surface-grafted polyglutamate films with a permanently perpendicular helix orientation were prepared. A surface-grafted alpha-helical polyglutamate film containing polymerizable side groups was synthesized by ring-opening terpolymerization of 50 molar% gamma-methyl-L-glutamate N-carboxyanhydride (NCA), 30% gamma-stearyl-L-glutamate NCA and 20% gamma-4-vinylbenzyl-L-glutamate NCA initiated from a silicon substrate functionalized with primary amino groups. The average tilt angle of the end-grafted helices in this film is approximately 66 degrees , indicating a nearly parallel helix orientation with respect to the substrate surface. After swelling of the grafted terpolyglutamate film in stearyl methacrylate and subsequent radical cross-linking, the average helix tilt angle decreases to about 11 degrees, indicating an almost perpendicular helix orientation. The film thickness increases accordingly from 151 A before to approximately 390 A after cross-linking. Extensive solvent treatment of the cross-linked film shows that the perpendicular helix orientation is permanent.
采用化学交联方法制备了具有永久垂直螺旋取向的表面接枝聚谷氨酸薄膜。通过50摩尔%的γ-甲基-L-谷氨酸N-羧基酐（NCA）、30%的γ-硬脂酰-L-谷氨酸NCA和20%的γ-4-乙烯基苄基-L-谷氨酸NCA的开环三元聚合反应，从用伯氨基官能化的硅基底引发合成了一种含有可聚合侧基的表面接枝α-螺旋聚谷氨酸薄膜。该薄膜中末端接枝螺旋的平均倾斜角约为66度，表明相对于基底表面具有近乎平行的螺旋取向。在接枝的三元聚谷氨酸薄膜在甲基丙烯酸硬脂酯中溶胀并随后进行自由基交联后，平均螺旋倾斜角减小到约11度，表明几乎是垂直的螺旋取向。薄膜厚度相应地从交联前的151埃增加到交联后的约390埃。对交联薄膜进行广泛的溶剂处理表明，垂直螺旋取向是永久性的。
