NMR Structural Studies of Antimicrobial Peptides: LPcin Analogs
| Autor: | Sung-Sub Choi, Yongae Kim, Ji-Sun Kim, Ji-Ho Jeong |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Antimicrobial peptides Amino Acid Motifs Molecular Sequence Data Biophysics Peptide Molecular Dynamics Simulation Micelle 03 medical and health sciences Membrane Lipids Anti-Infective Agents Amphiphile Amino Acid Sequence Micelles chemistry.chemical_classification Membranes Nuclear magnetic resonance spectroscopy Milk Proteins Peptide Fragments Amino acid Protein Structure Tertiary Crystallography 030104 developmental biology Membrane chemistry Heteronuclear single quantum coherence spectroscopy |
| Zdroj: | Biophysical Journal. 110(2):423-430 |
| ISSN: | 0006-3495 |
| DOI: | 10.1016/j.bpj.2015.12.006 |
| Popis: | Lactophoricin (LPcin), a component of proteose peptone (113-135) isolated from bovine milk, is a cationic amphipathic antimicrobial peptide consisting of 23 amino acids. We designed a series of N- or C-terminal truncated variants, mutated analogs, and truncated mutated analogs using peptide-engineering techniques. Then, we selected three LPcin analogs of LPcin-C8 (LPcin-YK1), LPcin-T2WT6W (LPcin-YK2), and LPcin-T2WT6W-C8 (LPcin-YK3), which may have better antimicrobial activities than LPcin, and successfully expressed them in E. coli with high yield. We elucidated the 3D structures and topologies of the three LPcin analogs in membrane environments by conducting NMR structural studies. We investigated the purity of the LPcin analogs and the α-helical secondary structures by performing (1)H-(15)N 2D HSQC and HMQC-NOESY liquid-state NMR spectroscopy using protein-containing micelle samples. We measured the 3D structures and tilt angles in membranes by conducting (15)N 1D and 2D (1)H-(15)N SAMMY type solid-state NMR spectroscopy with an 800 MHz in-house-built (1)H-(15)N double-resonance solid-state NMR probe with a strip-shield coil, using protein-containing large bicelle samples aligned and confirmed by molecular-dynamics simulations. The three LPcin analogs were found to be curved α-helical structures, with tilt angles of 55-75° for normal membrane bilayers, and their enhanced activities may be correlated with these topologies. |
| Databáze: | OpenAIRE |
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