The conformation of peptide thymosin α1 in solution and in a membrane-like environment by circular dichroism and NMR spectroscopy. a possible model for its interaction with the lymphocyte membrane

@article{Grottesi1998TheCO,
  title={The conformation of peptide thymosin $\alpha$1 in solution and in a membrane-like environment by circular dichroism and NMR spectroscopy. a possible model for its interaction with the lymphocyte membrane},
  author={Alessandro Grottesi and Marco Sette and Anna Teresa Palamara and Giuseppe Rotilio and Enrico Garaci and Maurizio Paci},
  journal={Peptides},
  year={1998},
  volume={19},
  pages={1731-1738}
}
The 28-residue peptide thymosin alpha1 was studied by circular dichroism and two-dimensional NMR. Circular dichroism indicates that thymosin alpha1 in water solution does not assume a preferred conformation, while in the presence of small unilamellar vesicles of dimiristoylphosphatidylcholine and dimiristoylphosphatidic acid (10:1) and in sodium dodecyl sulphate, it assumes a partly structured conformation. Presence of zinc ions produces similar effects. In a more hydrophobic environment like a… Expand
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References

SHOWING 1-10 OF 29 REFERENCES
Membrane-bound conformation of a signal peptide: a transferred nuclear Overhauser effect analysis.
TLDR
The conformation of an analogue of the Escherichia coli LamB signal peptide inserted into a model membrane using the transferred nuclear Overhauser effect (trNOE) NMR technique is determined and it is indicated that the residues in the helical region are well integrated into the acyl chain region of the bilayer. Expand
Structure, solubility and reactivity of peptides. A conformational study of two protected key intermediates from a large-scale synthesis of thymosin alpha 1.
A conformational study of two protected peptide segments, (1-10 and 11-28), spanning the entire sequence of thymosin alpha 1, in solvents of different polarity and capability of forming hydrogenExpand
Conformational behavior of Escherichia coli OmpA signal peptides in membrane mimetic environments.
Nuclear magnetic resonance and circular dichroism (CD) studies of isolated peptides corresponding to WT and mutant OmpA signal sequences are reported; all of the peptides adopt substantial amounts ofExpand
PhoE signal peptide inserts into micelles as a dynamic helix-break-helix structure, which is modulated by the environment. A two-dimensional 1H NMR study.
TLDR
To assess the conformational flexibility of signal sequences, the signal peptide of PhoE was studied by two-dimensional nuclear magnetic resonance and circular dichroism in different membrane mimetic environments and alpha-helix formation was observed. Expand
Proton NMR conformational study of an annexin I fragment: influence of a phospholipidic micellar environment.
TLDR
A 32 residue peptide spanning the first helix-loop-helix motif of the second repeat of human annexin I, was synthesized and studied by standard 2D proton NMR and molecular modeling, showing the potency of a membrane-like micellar environment to initiate peptide secondary structures and even elements of tertiary structure. Expand
Peptide environment specifies conformation. Helicity of hydrophobic segments compared in aqueous, organic, and membrane environments.
TLDR
Peptide helicity in organic solvents, membrane-mimetic SDS micelles, and negatively charged lipid bilayer vesicles, was found to be governed almost exclusively by the segmental hydrophobicity of the peptide mid-hydrophobic core segment. Expand
A chemically synthesized pre‐sequence of an imported mitochondrial protein can form an amphiphilic helix and perturb natural and artificial phospholipid bilayers.
TLDR
It is suggested that Amphiphilic helicity appears to be a general feature of mitochondrial pre‐sequences that plays a crucial role in transporting proteins into mitochondria. Expand
A model for the interaction of trifluoroethanol with peptides and proteins.
  • R. Rajan, P. Balaram
  • Chemistry, Medicine
  • International journal of peptide and protein research
  • 1996
TLDR
A model is proposed for TFE interaction with peptides which involves an initial replacement of the hydration shell by fluoroalcohol molecules, a process driven by apolar interactions and favourable entropy of dehydration. Expand
Calculation of protein conformation from circular dichroism.
TLDR
This chapter discusses some recent developments in the estimation of various conformations in a protein molecule from its circular dichroism (CD) spectrum in the ultraviolet region. Expand
Nuclear targeting of prothymosin alpha.
TLDR
The basic cluster of amino acids at the carboxyl terminus of prothymosin alpha, TKKQKT, has been identified as part of the nuclear targeting signal, whereas the basic clusterof amino acids situated within the thymos in alpha 1 sequence at the amino terminus failed to effect nuclear transport. Expand
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1
2
3
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