Vicente Fidel E Morales, González-Garcia Melaine, Diaz Pico Erbio, Moreno-Castillo Elena, Garay Hilda E, Rosi Pablo E, Jimenez Asiel Mena, Campos-Delgado Jose A, Rivera Daniel G, Chinea Glay, Pietro Rosemeire C L R, Stenger Steffen, Spellerberg Barbara, Kubiczek Dennis, Bodenberger Nicholas, Dietz Steffen, Rosenau Frank, Paixão Márcio Weber, Ständker Ludger, Otero-González Anselmo J
General Chemistry Department, Faculty of Chemistry and Center for Natural Products Research, Faculty of Chemistry, University of Havana, Zapata y G, 10400 La Habana, Cuba.
Synthetic Peptides Group, Center for Genetic Engineering and Biotechnology, P.O. Box 6162, 10600 La Habana, Cuba.
ACS Omega. 2019 Nov 5;4(21):19081-19095. doi: 10.1021/acsomega.9b02201. eCollection 2019 Nov 19.
Following the information obtained by a rational design study, a cyclic and helical-stabilized analogue of the peptide Cm-p5 was synthetized. The cyclic monomer showed an increased activity in vitro against and , compared to Cm-p5. Initially, 14 mutants of Cm-p5 were synthesized following a rational design to improve the antifungal activity and pharmacological properties. Antimicrobial testing showed that the activity was lost in each of these 14 analogues, suggesting, as a main conclusion, that a Glu-His salt bridge could stabilize Cm-p5 helical conformation during the interaction with the plasma membrane. A derivative, obtained by substitution of Glu and His for Cys, was synthesized and oxidized with the generation of a cyclic monomer with improved antifungal activity. In addition, two dimers were generated during the oxidation procedure, a parallel and antiparallel one. The dimers showed a helical secondary structure in water, whereas the cyclic monomer only showed this conformation in SDS. Molecular dynamic simulations confirmed the helical stabilizations for all of them, therefore indicating the possible essential role of the Glu-His salt bridge. In addition, the antiparallel dimer showed a moderate activity against and a significant activity against . Neither the cyclic monomer nor the dimers were toxic against macrophages or THP-1 human cells. Due to its increased capacity for fungal control compared to fluconazole, its low cytotoxicity, together with a stabilized α-helix and disulfide bridges, that may advance its metabolic stability, and in vivo activity, the new cyclic Cm-p5 monomer represents a potential systemic antifungal therapeutic candidate.
根据合理设计研究获得的信息，合成了肽Cm-p5的环状和螺旋稳定类似物。与Cm-p5相比，环状单体在体外对[具体菌种1]和[具体菌种2]显示出增强的活性。最初，按照合理设计合成了14种Cm-p5突变体，以提高其抗真菌活性和药理特性。抗菌测试表明，这14种类似物中的每一种活性均丧失，这表明，作为主要结论，谷氨酸-组氨酸盐桥在与质膜相互作用期间可稳定Cm-p5的螺旋构象。合成了一种通过用半胱氨酸取代谷氨酸和组氨酸获得的衍生物，并将其氧化生成具有改善抗真菌活性的环状单体。此外，在氧化过程中生成了两种二聚体，一种是平行二聚体，一种是反平行二聚体。二聚体在水中显示出螺旋二级结构，而环状单体仅在十二烷基硫酸钠（SDS）中显示出这种构象。分子动力学模拟证实了它们所有的螺旋稳定性，因此表明谷氨酸-组氨酸盐桥可能具有重要作用。此外，反平行二聚体对[具体菌种1]显示出中等活性，对[具体菌种2]显示出显著活性。环状单体和二聚体对巨噬细胞或THP-1人细胞均无毒性。与氟康唑相比，新的环状Cm-p5单体具有更强的真菌控制能力、低细胞毒性，以及稳定的α-螺旋和二硫键，这可能会提高其代谢稳定性和体内活性，因此它是一种潜在的全身性抗真菌治疗候选物。
