Institute for Scintillation Materials of NAS of Ukraine, 60 Nauky Ave., 61172 Kharkiv, Ukraine.
Department of Molecular and Medical Biophysics, V. N. Karazin Kharkiv National University, 4 Svobody Sq., 61022 Kharkiv, Ukraine.
Int J Mol Sci. 2024 Aug 9;25(16):8691. doi: 10.3390/ijms25168691.
Gramicidin S (GS), one of the first discovered antimicrobial peptides, still shows strong antibiotic activity after decades of clinical use, with no evidence of resistance. The relatively high hemolytic activity and narrow therapeutic window of GS limit its use in topical applications. Encapsulation and targeted delivery may be the way to develop the internal administration of this drug. The lipid composition of membranes and non-covalent interactions affect GS's affinity for and partitioning into lipid bilayers as monomers or oligomers, which are crucial for GS activity. Using both differential scanning calorimetry (DSC) and FTIR methods, the impact of GS on dipalmitoylphosphatidylcholine (DPPC) membranes was tested. Additionally, the combined effect of GS and cholesterol on membrane characteristics was observed; while dipalmitoylphosphatydylglycerol (DPPG) and cerebrosides did not affect GS binding to DPPC membranes, cholesterol significantly altered the membrane, with 30% mol concentration being most effective in enhancing GS binding. The effect of star-like dextran-polyacrylamide D-g-PAA(PE) on GS binding to the membrane was tested, revealing that it interacted with GS in the membrane and significantly increased the proportion of GS oligomers. Instead, calcium ions affected GS binding to the membrane differently, with independent binding of calcium and GS and no interaction between them. This study shows how GS interactions with lipid membranes can be effectively modulated, potentially leading to new formulations for internal GS administration. Modified liposomes or polymer nanocarriers for targeted GS delivery could be used to treat protein misfolding disorders and inflammatory conditions associated with free-radical processes in cell membranes.
短杆菌肽 S(GS)是最早发现的抗菌肽之一,经过几十年的临床应用,仍然表现出很强的抗菌活性,没有耐药的证据。GS 相对较高的溶血活性和较窄的治疗窗口限制了其在局部应用中的使用。包封和靶向递送可能是开发这种药物内服应用的方法。膜的脂质组成和非共价相互作用影响 GS 作为单体或寡聚物对脂质双层的亲和力和分配,这对 GS 的活性至关重要。本研究使用差示扫描量热法(DSC)和傅里叶变换红外光谱(FTIR)方法测试了 GS 对二棕榈酰磷脂酰胆碱(DPPC)膜的影响。此外,还观察了 GS 和胆固醇对膜特性的联合影响;虽然二棕榈酰磷脂酰甘油(DPPG)和脑苷脂不影响 GS 与 DPPC 膜的结合,但胆固醇显著改变了膜,其中 30%摩尔浓度最有效地增强 GS 结合。还测试了星形葡聚糖-聚丙烯酰胺 D-g-PAA(PE)对 GS 与膜结合的影响,结果表明它与膜中的 GS 相互作用,显著增加了 GS 寡聚物的比例。相反,钙离子对 GS 与膜结合的影响不同,钙和 GS 独立结合,它们之间没有相互作用。这项研究表明如何有效地调节 GS 与脂质膜的相互作用,这可能为内部 GS 给药的新配方提供依据。用于靶向 GS 递送的改良脂质体或聚合物纳米载体可用于治疗与细胞膜中自由基过程相关的蛋白质错误折叠疾病和炎症。