Structure-activity analysis of buforin II, a histone H2A-derived antimicrobial peptide: The proline hinge is responsible for the cell-penetrating ability of buforin II
Structure-activity analysis of buforin II, a histone H2A-derived antimicrobial peptide: The proline hinge is responsible for the cell-penetrating ability of buforin II
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DOI：
10.1073/pnas.150518097
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发表时间：
2000-07-18
影响因子：
11.1
通讯作者：
Kim, SC
中科院分区：
文献类型：
--
作者：
Park, CB;Yi, KS;Kim, SC
Buforin II是一种由21个氨基酸组成的有效抗菌肽，在疏水介质中形成由N-末端无规卷曲区域组成的两亲性结构（残基1-4），延伸的螺旋区域（残基5-10），铰链（残基11）和C-末端规则α-螺旋区域（残基12-21），为了阐明buforin II的有效抗微生物活性所需的结构特征，我们合成了一系列N-和C-末端截短或氨基酸取代的合成buforin II类似物，并检测了它们的抗微生物活性和作用机制。N-末端无规卷曲区域的缺失使抗菌活性增加约2倍，但进一步的N-末端截短产生活性逐渐降低的肽类似物。从蟾毒灵II的C-末端去除四个氨基酸导致抗微生物活性的完全丧失。亮氨酸取代脯氨酸铰链显着降低抗菌活性。共聚焦荧光显微镜研究表明，buforin II类似物与脯氨酸铰链穿透细胞膜没有透化和积累在细胞质中。然而，去除脯氨酸铰链废除的肽进入细胞的能力，和buforin II类似物没有脯氨酸铰链定位在细胞表面上，透化细胞膜，此外，buforin II及其截短的类似物，这取决于铜螺旋含量的肽的细胞穿透效率，与它们的抗菌效力线性相关。我们的研究结果清楚地表明，脯氨酸铰链是负责buforin II的细胞穿透能力，和细胞穿透效率决定的肽的抗菌效力。
Buforin II is a 21-aa potent antimicrobial peptide that forms, in a hydrophobic medium, an amphipathic structure consisting of an N-terminal random coil region (residues 1-4), an extended helical region (residues 5-10), a hinge (residue 11), and a C-terminal regular alpha-helical region (residues 12-21), To elucidate the structural features of buforin II that are required for its potent antimicrobial activity, we synthesized a series of N- and C-terminally truncated or amino acid-substituted synthetic buforin II analogs and examined their antimicrobial activity and mechanism of action. Deletion of the N-terminal random coil region increased the antibacterial activity approximate to 2-fold, but further N-terminal truncation yielded peptide analogs with progressively decreasing activity. Removal of four amino acids from the C-terminal end of buforin II resulted in a complete loss of antimicrobial activity. The substitution of leucine for the proline hinge decreased significantly the antimicrobial activity. Confocal fluorescence microscopic studies showed that buforin II analogs with a proline hinge penetrated the cell membrane without permeabilization and accumulated in the cytoplasm. However, removal of the proline hinge abrogated the ability of the peptide to enter cells, and buforin II analogs without a proline hinge localized on the cell surface, permeabilizing the cell membrane, In addition, the cell-penetrating efficiency of buforin II and its truncated analogs, which depended on the cu-helical content of the peptides, correlated linearly with their antimicrobial potency. Our results demonstrate clearly that the proline hinge is responsible for the cell-penetrating ability of buforin II, and the cell-penetrating efficiency determines the antimicrobial potency of the peptide.