Zhong Yang, Li Bingyun, Haynie Donald T
Biomedical Engineering and Physics, Bionanosystems Engineering Laboratory, Center for Applied Physics Studies, Louisiana Tech University, PO Box 10137, Ruston, Louisiana 71272, USA.
Biotechnol Prog. 2006 Jan-Feb;22(1):126-32. doi: 10.1021/bp050130h.
Adjustment of pH can alter the ensemble of three-dimensional structures of a polypeptide in solution by changing the distribution of charge and Coulombic interactions. The role of pH in layer-by-layer self-assembly (LbL) of designed 32mer peptides containing the amino acid cysteine has been investigated using a combination of physical methods. Results show that pH can have a substantial influence on the mass of adsorbed peptide, surface roughness, and film density over a range of 1.5 pH units. Peptide film thickness depends on the number of layers, as with "conventional" polyelectrolytes. Film density and morphology, however, vary more with pH than does thickness, translating into a change in density on the order of 70% over the pH range 7.4-8.9. Results of this work provide insight on the physical basis of LbL and suggest that peptides are a promising class of polyelectrolytes for the creation of designer thin films for applications in biotechnology and other areas.
调节pH值可以通过改变电荷分布和库仑相互作用来改变溶液中多肽的三维结构组合。利用多种物理方法研究了pH值在含半胱氨酸的32聚体设计肽的逐层自组装（LbL）中的作用。结果表明，在1.5个pH单位范围内，pH值对吸附肽的质量、表面粗糙度和膜密度有显著影响。肽膜厚度取决于层数，与“传统”聚电解质一样。然而，膜密度和形态随pH值的变化比厚度变化更大，在pH值7.4 - 8.9范围内，密度变化约为70%。这项工作的结果为LbL的物理基础提供了见解，并表明肽是一类很有前途的聚电解质，可用于制备用于生物技术和其他领域的定制薄膜。
