Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1.
Centre for Blood Research, Department of Pathology and Laboratory Medicine, University of British Columbia , 2350 Health Sciences Mall, Life Sciences Centre, Vancouver, BC, Canada V6T 1Z3.
ACS Appl Mater Interfaces. 2017 Nov 1;9(43):37575-37586. doi: 10.1021/acsami.7b09471. Epub 2017 Oct 19.
We report the synthesis, characterization, activity, and biocompatibility of a novel series of antimicrobial peptide-polymer conjugates. Using parent peptide aurein 2.2, we designed a peptide array (∼100 peptides) with single and multiple W and R mutations and identified antimicrobial peptides (AMPs) with potent activity against Staphylococcus aureus (S. aureus). These novel AMPs were conjugated to hyperbranched polyglycerols (HPGs) of different molecular weights and number of peptides to improve their antimicrobial activity and toxicity. The cell and blood compatibility studies of these conjugates demonstrated better properties than those of the AMP alone. However, conjugates showed lower antimicrobial activity in comparison to that of peptides, as determined from minimal inhibition concentrations (MICs) against S. aureus, but considerably better than that of the available polymer-AMP conjugates in the literature. In addition to measuring MICs and characterizing the biocompatibility, circular dichroism spectroscopy was used to investigate the interaction of the novel conjugates with model bacterial biomembranes. Moreover, the novel conjugates were exposed to trypsin to evaluate their stability. It was found that the conjugates resist proteolysis in comparison with unprotected peptides. The peptide conjugates were active in serum and whole blood. Overall, the results show that combining a highly active AMP and low-molecular-weight HPG yields bioconjugates with excellent biocompatibility, MICs below 100 μg/mL, and proteolytic stability, which could potentially improve its utility for in vivo applications.
我们报告了一系列新型抗菌肽-聚合物缀合物的合成、表征、活性和生物相容性。使用母体肽 aurein 2.2，我们设计了一个具有单个和多个 W 和 R 突变的肽阵列（~100 个肽），并鉴定出对金黄色葡萄球菌（S. aureus）具有强活性的抗菌肽（AMPs）。这些新型 AMP 与不同分子量和肽数的支化聚甘油（HPG）缀合，以提高其抗菌活性和毒性。这些缀合物的细胞和血液相容性研究表明，它们的性质优于单独的 AMP。然而，与肽相比，缀合物的抗菌活性较低，这是根据最小抑菌浓度（MIC）对金黄色葡萄球菌的测定结果得出的，但与文献中现有聚合物-AMP 缀合物相比，其抗菌活性要好得多。除了测量 MIC 和表征生物相容性外，圆二色光谱还用于研究新型缀合物与模型细菌生物膜的相互作用。此外，还对新型缀合物进行了胰蛋白酶处理，以评估其稳定性。结果发现，与未保护的肽相比，缀合物具有抵抗蛋白水解的作用。肽缀合物在血清和全血中均具有活性。总的来说，结果表明，将高活性的 AMP 和低分子量的 HPG 结合起来，可以得到具有优异生物相容性、MIC 值低于 100μg/ml 和蛋白水解稳定性的生物缀合物，这可能会提高其在体内应用的实用性。
