6533b836fe1ef96bd12a1568
RESEARCH PRODUCT
The Surfactant Peptide KL4 Sequence Is Inserted with a Transmembrane Orientation into the Endoplasmic Reticulum Membrane
Jesús Pérez-gilLuis Martínez-gilIsmael Mingarrosubject
Models MolecularBiophysical LettersProtein ConformationBiophysicsBiologyEndoplasmic ReticulumCell membraneProtein structurePulmonary surfactantMembranes (Biologia)medicineAnimalsHumansPulmonary surfactant-associated protein BAmino Acid SequencePeptide sequencePulmonary Surfactant-Associated Protein BEndoplasmic reticulumCell MembraneInfant NewbornTransmembrane proteinMembranemedicine.anatomical_structureBiochemistryBiophysicsPèptidsPeptidesHydrophobic and Hydrophilic Interactionsdescription
AbstractSurfactant 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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2008-09-01 | Biophysical Journal |