Development of nonfouling polypeptides with uniform alternating charges by polycondensation of the covalently bonded dimer of glutamic acid and lysine
作者:Qinghua Yang、Longgang Wang、Weifeng Lin、Guanglong Ma、Jiang Yuan、Shengfu Chen
DOI:10.1039/c3tb21333a
日期:——
In this work, nonfouling polypeptides with homogenous alternating charges were synthesized by polycondensation of the covalently bonded dimer of glutamic acid (E) and lysine (K) (EK dimer) with benzyloxycarbonyl (Z)-protected side chains. This facile method successfully solved the uniformity problem of nonfouling peptides caused by the copolymerization of two different monomers and enabled the incorporation of various terminal functional groups for future applications. The molecular weights (MWs) of the nonfouling peptides can be easily controlled by the ratio of the terminal group, lipoic acid, to the EK dimer. The nonfouling peptides can form self-assembling monolayers (SAMs) on a gold surface through two terminal thiol groups, which were characterized by attenuated total reflection Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and ellipsometry (ELL). The resistance to nonspecific protein adsorption, cell attachment and bacterial adhesion of these nonfouling peptide SAMs and the in vitro cytotoxicity and haemolytic activity of these peptides were also evaluated. The results show that the lowest relative protein adsorptions of antibody (anti-IgG) and fibrinogen (Fg) on the SAMs are 5.1 ± 1.6% and 7.3 ± 1.8%, respectively, determined by enzyme-linked immunosorbent assay (ELISA), where the protein adsorption on a tissue culture polystyrene (TCPS) surface was set to 100%. Almost no obvious cell attachment and bacterial adhesion were observed, and no cytotoxicity and no haemolytic activity in vitro were detected. With the advantages of biocompatibility, biodegradability and the abundance of moieties for ligand immobilization, these nonfouling peptides developed by the facile method can be used in a wide range of biomedical applications.
这项研究通过将谷氨酸(E)和赖氨酸(K)的共价键二聚体(EK 二聚体)与苄氧羰基(Z)保护侧链缩聚,合成了具有均匀交替电荷的防污多肽。这种简便的方法成功地解决了两种不同单体共聚造成的多肽不均匀性问题,并能加入各种末端官能团,以满足未来的应用需求。通过端基硫辛酸与 EK 二聚体的比例,可以轻松控制防污肽的分子量(MWs)。通过衰减全反射傅立叶变换红外光谱(ATR-FTIR)、X 射线光电子能谱(XPS)和椭偏仪(ELL)对其进行了表征。此外,还评估了这些无垢多肽 SAM 对非特异性蛋白质吸附、细胞附着和细菌粘附的抗性,以及这些多肽的体外细胞毒性和溶血活性。结果表明,通过酶联免疫吸附试验(ELISA)测定,抗体(抗 IgG)和纤维蛋白原(Fg)在 SAMs 上的最低相对蛋白质吸附率分别为 5.1 ± 1.6% 和 7.3 ± 1.8%,组织培养聚苯乙烯(TCPS)表面的蛋白质吸附率设定为 100%。几乎没有观察到明显的细胞附着和细菌粘附,也没有检测到体外细胞毒性和溶血活性。由于具有生物相容性、生物可降解性和丰富的配体固定分子等优点,这种简便方法制备的非污损肽可广泛应用于生物医学领域。