Wang Bo, Feng Jie, Gao Changyou
Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Macromol Biosci. 2005 Aug 12;5(8):767-74. doi: 10.1002/mabi.200500037.
Various biomacromolecules including proteins and polysaccharides are printed on a substrate capped with a bovine serum albumin (BSA) precursor layer to create clear co-patterns of these molecules. Characterizations by confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM) demonstrate the successful production and clear boundaries of the co-patterns. Rinsing the BSA-adsorbed substrate and the biomacromolecules-inked stamp before microcontact printing (microCP) is crucial for the creation of clear and stable co-patterns. The patterns are mainly stabilized by electrostatic interactions and van der Waals forces. Characterizations by ellipsometry, UV-Vis and fluorescence spectroscopy reveal that printing by a flat PDMS stamp yields a denser layered structure of proteins with a higher amount than that of adsorbed proteins. By printing, however, a lower enzymatic catalytic activity for horseradish peroxidase (HRP) or binding capability for avidin (both normalized to amount) is determined. A conformational transition from alpha-helix to beta-sheet of HRP is observed by ATR-IR. By contrast, a BSA precursor layer can effectively improve the functionality of the printed HRP or avidin and preserve the original conformation of the proteins, although the absolute transferred amount of these proteins is decreased.
包括蛋白质和多糖在内的各种生物大分子被打印在覆盖有牛血清白蛋白（BSA）前体层的基底上，以形成这些分子的清晰共图案。通过共聚焦激光扫描显微镜（CLSM）和原子力显微镜（AFM）进行的表征证明了共图案的成功制备及其清晰的边界。在微接触印刷（microCP）之前冲洗吸附了BSA的基底和带有生物大分子的印章对于创建清晰且稳定的共图案至关重要。这些图案主要通过静电相互作用和范德华力得以稳定。通过椭偏仪、紫外可见光谱和荧光光谱进行的表征表明，使用平面聚二甲基硅氧烷（PDMS）印章进行印刷会产生比吸附蛋白质数量更多、结构更致密的蛋白质层状结构。然而，通过印刷测定发现，辣根过氧化物酶（HRP）的酶催化活性或抗生物素蛋白的结合能力（均按数量归一化）较低。通过衰减全反射红外光谱（ATR-IR）观察到HRP从α-螺旋向β-折叠的构象转变。相比之下，尽管这些蛋白质的绝对转移量有所减少，但BSA前体层可以有效提高印刷的HRP或抗生物素蛋白的功能，并保留蛋白质的原始构象。
