The surfactant peptide KL4 sequence is inserted with a transmembrane orientation into the endoplasmic reticulum membrane
The surfactant peptide KL4 sequence is inserted with a transmembrane orientation into the endoplasmic reticulum membrane
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DOI：
10.1529/biophysj.108.138602
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发表时间：
2008-09-15
影响因子：
3.4
通讯作者：
Mingarro, Ismael
中科院分区：
文献类型：
--
作者：
Martinez-Gil, Luis;Perez-Gil, Jesus;Mingarro, Ismael
Surfactant protein B (SP-B) is an essential component of pulmonary surfactant. Synthetic surfactant peptide KL4, a peptide based on a C-terminal amphipathic helical region of human SP-B, efficiently mimics some functional properties of SP-B and is included in therapeutic surfactant preparations used in trials to treat respiratory distress syndrome. The membrane orientation of this peptide is controversial. We used an in vitro transcription-translation system to study the insertion of hydrophobic sequences into microsomal membranes, and showed that the KL4 sequence integrates efficiently with a transmembrane orientation despite the presence of intermittent lysines throughout the sequence. In contrast, the precise sequence of the C-terminal SP-B amphipathic region failed to integrate, indicating a nontransmembrane orientation. Differences in the membrane insertion between KL4 and the SP-B-inspiring sequence match predictions from calculated free energies of insertion of the two sequences into membranes.
