Brevinin‐1BYa (FLPILASLAAKFGPKLFCLVTKKC), first isolated from skin secretions of the foothill yellow‐legged frog Rana boylii, shows broad‐spectrum activity, being particularly effective against opportunistic yeast pathogens. The structure of brevinin‐1BYa was investigated in various solution and membrane‐mimicking environments by proton nuclear magnetic resonance (¹H‐NMR) spectroscopy and molecular modelling. The peptide does not possess a secondary structure in aqueous solution. In a 33% 2,2,2‐trifluoroethanol (TFE‐d₃)‐H₂O solvent mixture, as well as in membrane‐mimicking sodium dodecyl sulfate and dodecylphosphocholine micelles, the peptide's structure is characterised by a flexible helix‐hinge‐helix motif, with the hinge located at the Gly¹³/Pro¹⁴ residues, and the two α‐helices extending from Pro³ to Phe¹² and from Pro¹⁴ to Thr²¹. Positional studies involving the peptide in sodium dodecyl sulfate and dodecylphosphocholine micelles using 5‐doxyl‐labelled stearic acid and manganese chloride paramagnetic probes show that the peptide's helical segments lie parallel to the micellar surface, with the residues on the hydrophobic face of the amphipathic helices facing towards the micelle core and the hydrophilic residues pointing outwards, suggesting that the peptide exerts its biological activity by a non–pore‐forming mechanism.

中文翻译：

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在膜模拟环境中抗菌肽brevinin-1BYa的结构和位置研究。

布雷维宁-1BYa（FLPILASLAAKFGPKLFCLVTKKC）最初从山麓黄脚蛙蛙蛙的皮肤分泌物中分离出来，具有广谱活性，对机会性酵母病原体特别有效。通过质子核磁共振（¹ H-NMR）光谱和分子建模，研究了在各种溶液和膜模拟环境中brevinin-1BYa的结构。该肽在水溶液中不具有二级结构。在33％2,2,2-三氟乙醇（TFE-d ₃）-H _2中作为溶剂混合物，以及在类似于膜的十二烷基硫酸钠和十二烷基磷酸胆碱胶束中，该肽的结构具有灵活的螺旋-铰链-螺旋基序，其铰链位于Gly ¹³ / Pro ¹⁴残基上，两个α螺旋从Pro ³延伸到Phe ¹²，从Pro ¹⁴延伸到Thr ²¹。使用5-doxyl标记的硬脂酸和氯化锰顺磁性探针对涉及十二烷基硫酸钠和十二烷基磷酸胆碱胶束中肽的位置研究表明，该肽的螺旋段与胶束表面平行，且残基在两亲螺旋的疏水面上朝向胶束核心，亲水性残基朝外，表明该肽通过非孔形成机制发挥其生物学活性。