Dynamic Structure of Disulfide-Removed Linear Analogs of Tachyplesin-I in the Lipid Bilayer from Solid-State NMR

Doherty, Tim; Waring, and Alan J.; Hong, Mei

doi:10.1021/bi701390t

“…These dynamic differences were observed from temperature-dependent 13 C intensities, motionally averaged couplings, and spin relaxation times. 35 These data suggest that TP-I and TPF4 disrupt the lipid membrane by in-plane diffusion, where the interfacial-located peptides diffuse around the bilayer normal to cause membrane defects. 35 [ Fig.…”

Section: Tachyplesin-imentioning

confidence: 87%

“…35 These data suggest that TP-I and TPF4 disrupt the lipid membrane by in-plane diffusion, where the interfacial-located peptides diffuse around the bilayer normal to cause membrane defects. 35 [ Fig. 3(b)].…”

Section: Tachyplesin-imentioning

confidence: 87%

“…Thus, neither conformation nor depth correlates with the activity profile of the three peptides. 35 Instead, the mobility profile does. The active TP-I and TPF4 both show fast segmental and global motions in the membrane, whereas TPA4 is immobilized.…”

Section: Tachyplesin-imentioning

confidence: 99%

“…33,34 Immobilization of a small polypeptide is usually a sign of its oligomerization in the membrane, whereas fast uniaxial rotational diffusion is usually associated with monomeric molecules and can disrupt lipid packing in the membrane. 35 Motional effects manifest in NMR spectra as line narrowing for fast, submicrosecond, motions, exchange broadening for intermediate-timescale motions, and cross peaks between conformationally different states for slow millisecond motions. The most robust approach to detect fast motion by NMR is to measure one-bond CAH and NAH dipolar couplings using 2D separated local field experiments, 36 which resolve the couplings of different sites according to their isotropic chemical shifts.…”

Section: Solid-state Nmr Techniques For Studying Protein-membrane Intmentioning

confidence: 99%

See 2 more Smart Citations

Structure and dynamics of cationic membrane peptides and proteins: Insights from solid‐state NMR

Hong¹,

Su²

2011

Self Cite

View full text Add to dashboard Cite

Many membrane peptides and protein domains contain functionally important cationic Arg and Lys residues, whose insertion into the hydrophobic interior of the lipid bilayer encounters significant energy barriers. To understand how these cationic molecules overcome the free energy barrier to insert into the lipid membrane, we have used solid-state NMR spectroscopy to determine the membrane-bound topology of these peptides. A versatile array of solid-state NMR experiments now readily yields the conformation, dynamics, orientation, depth of insertion, and site-specific protein-lipid interactions of these molecules. We summarize key findings of several Arg-rich membrane peptides, including b-sheet antimicrobial peptides, unstructured cell-penetrating peptides, and the voltage-sensing helix of voltage-gated potassium channels. Our results indicate the central role of guanidinium-phosphate and guanidinium-water interactions in dictating the structural topology of these cationic molecules in the lipid membrane, which in turn account for the mechanisms of this functionally diverse class of membrane peptides.

show abstract

“…The data herein suggest that the remaining activity of Arg mm -PG-1 is achieved by a different mechanism, most likely in-plane diffusion, which still gives rise to isotropic lipid morphologies, albeit at a lower level than the toroidal pore mechanism employed by wild-type PG-1. [18] Gdn-PO 4 À hydrogen bonding may also affect the structure and function of other Arg-rich membrane proteins, as suggested by recent molecular dynamics simulations of a potassium channel and a cell-penetrating peptide. [3,5,6] Experimental Section Arg mm -PG-1 is synthesized by Fmoc chemistry and purified to greater than 95 %.…”

mentioning

confidence: 97%

Effects of Guanidinium–Phosphate Hydrogen Bonding on the Membrane‐Bound Structure and Activity of an Arginine‐Rich Membrane Peptide from Solid‐State NMR Spectroscopy

Tang

¹

,

Waring

²

,

Lehrer

³

et al. 2008

Self Cite

View full text Add to dashboard Cite

Arginine-and lysine-rich cationic peptides and protein domains are found in a wide range of membrane-active proteins such as antimicrobial peptides, [1] cell-penetrating peptides, [2] and voltage-sensing domains of potassium channels.[3] Yet the three-dimensional structures these proteins adopt to enable translocation of the charged residues into the low dielectric milieu of the hydrophobic part of the lipid membrane, despite the free-energy barrier, [4] remain poorly understood. An increasing number of molecular dynamics simulations and experimental studies have suggested the importance of Arg interactions with lipids in membrane protein function. [5,6] Magic-angle spinning (MAS) solid-state NMR (SSNMR) spectroscopy can provide direct experimental insights into these intriguing questions of energetics and structure.We have recently reported SSNMR distance-constrained guanidinium-phosphate (Gdn-PO 4 À ) complex formation between the Arg residues of a b-hairpin antimicrobial peptide, PG-1, and the lipid phosphate groups.[7] The existence of these complexes suggests that the Arg residues are neutralized by the phosphate groups to enable transmembrane insertion of the peptide. We hypothesized that the peptide-associated phosphate headgroups transferred to the hydrophobic part of the membrane are responsible for the toroidal pore defects.[8] Such Gdn-PO 4 À complexes should be stabilized by NÀH···O=P hydrogen bonds and electrostatic attractions.[9]Herein we test the importance of Gdn-PO 4 À hydrogen bonding to the structure and activity of PG-1 by dimethylating each guanidinium group, thus reducing the number of N À H hydrogen-bond donors (Figure 1). [10] We show that this dimethylation of the Arg groups significantly alters the membrane insertion and activity of PG-1. Without the peptide, the membranes uniaxially aligned on glass plates and exhibited the expected single peak at approximately 30 ppm without other intensities in the anisotropic chemical shift range. Residual powder intensities indicative of misalignment and a small 0 ppm isotropic peak indicative of toroidal pores are observed with increasing concentrations of Arg mm -PG-1. Line-shape simulations indicate that the isotropic component in the 4 % Arg mm -PG-1 sample is 20 % of the total intensity, much less than the 39 % caused by PG-1; thus, dimethylation of the Arg residues reduces membrane disruption.Corroborating the 31 P NMR data are the minimal effective concentrations (MECs) of Arg mm -PG-1 and PG-1 against P NMR spectra of POPC/POPG membranes with 0-4 % a) Arg mm -PG-1 and b) PG-1. The 4 % sample spectra are simulated with an aligned peak, an isotropic peak, and a powder pattern, to yield the fraction of the isotropic peak.

show abstract

Effects of Guanidinium–Phosphate Hydrogen Bonding on the Membrane‐Bound Structure and Activity of an Arginine‐Rich Membrane Peptide from Solid‐State NMR Spectroscopy

Tang¹,

Waring²,

Lehrer³

et al. 2008

Self Cite

View full text Add to dashboard Cite

Arginine-and lysine-rich cationic peptides and protein domains are found in a wide range of membrane-active proteins such as antimicrobial peptides, [1] cell-penetrating peptides, [2] and voltage-sensing domains of potassium channels.[3] Yet the three-dimensional structures these proteins adopt to enable translocation of the charged residues into the low dielectric milieu of the hydrophobic part of the lipid membrane, despite the free-energy barrier, [4] remain poorly understood. An increasing number of molecular dynamics simulations and experimental studies have suggested the importance of Arg interactions with lipids in membrane protein function. [5,6] Magic-angle spinning (MAS) solid-state NMR (SSNMR) spectroscopy can provide direct experimental insights into these intriguing questions of energetics and structure.We have recently reported SSNMR distance-constrained guanidinium-phosphate (Gdn-PO 4 À ) complex formation between the Arg residues of a b-hairpin antimicrobial peptide, PG-1, and the lipid phosphate groups.[7] The existence of these complexes suggests that the Arg residues are neutralized by the phosphate groups to enable transmembrane insertion of the peptide. We hypothesized that the peptide-associated phosphate headgroups transferred to the hydrophobic part of the membrane are responsible for the toroidal pore defects.[8] Such Gdn-PO 4 À complexes should be stabilized by NÀH···O=P hydrogen bonds and electrostatic attractions.[9]Herein we test the importance of Gdn-PO 4 À hydrogen bonding to the structure and activity of PG-1 by dimethylating each guanidinium group, thus reducing the number of N À H hydrogen-bond donors (Figure 1). [10] We show that this dimethylation of the Arg groups significantly alters the membrane insertion and activity of PG-1. Without the peptide, the membranes uniaxially aligned on glass plates and exhibited the expected single peak at approximately 30 ppm without other intensities in the anisotropic chemical shift range. Residual powder intensities indicative of misalignment and a small 0 ppm isotropic peak indicative of toroidal pores are observed with increasing concentrations of Arg mm -PG-1. Line-shape simulations indicate that the isotropic component in the 4 % Arg mm -PG-1 sample is 20 % of the total intensity, much less than the 39 % caused by PG-1; thus, dimethylation of the Arg residues reduces membrane disruption.Corroborating the 31 P NMR data are the minimal effective concentrations (MECs) of Arg mm -PG-1 and PG-1 against P NMR spectra of POPC/POPG membranes with 0-4 % a) Arg mm -PG-1 and b) PG-1. The 4 % sample spectra are simulated with an aligned peak, an isotropic peak, and a powder pattern, to yield the fraction of the isotropic peak.

show abstract

Dynamic Structure of Disulfide-Removed Linear Analogs of Tachyplesin-I in the Lipid Bilayer from Solid-State NMR

Cited by 40 publications

References 53 publications

Structure and dynamics of cationic membrane peptides and proteins: Insights from solid‐state NMR

Structure and dynamics of cationic membrane peptides and proteins: Insights from solid‐state NMR

Effects of Guanidinium–Phosphate Hydrogen Bonding on the Membrane‐Bound Structure and Activity of an Arginine‐Rich Membrane Peptide from Solid‐State NMR Spectroscopy

Effects of Guanidinium–Phosphate Hydrogen Bonding on the Membrane‐Bound Structure and Activity of an Arginine‐Rich Membrane Peptide from Solid‐State NMR Spectroscopy

Contact Info

Product

Resources

About