1RG4

SP-B C-terminal peptide in organic solvent (HFIP)


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 40 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with favorable non-bond energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

NMR Structures of the C-Terminal Segment of Surfactant Protein B in Detergent Micelles and Hexafluoro-2-propanol.

Booth, V.Waring, A.J.Walther, F.J.Keough, K.M.

(2004) Biochemistry 43: 15187-15194

  • DOI: 10.1021/bi0481895
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Although the membrane-associated surfactant protein B (SP-B) is an essential component of lung surfactant, which is itself essential for life, the molecular basis for its activity is not understood. SP-B's biophysical functions can be partially mimic ...

    Although the membrane-associated surfactant protein B (SP-B) is an essential component of lung surfactant, which is itself essential for life, the molecular basis for its activity is not understood. SP-B's biophysical functions can be partially mimicked by subfragments of the protein, including the C-terminus. We have used NMR to determine the structure of a C-terminal fragment of human SP-B that includes residues 63-78. Structure determination was performed both in the fluorinated alcohol hexafluoro-2-propanol (HFIP) and in sodium dodecyl sulfate (SDS) micelles. In both solvents, residues 68-78 take on an amphipathic helical structure, in agreement with predictions made by comparison to homologous saposin family proteins. In HFIP, the five N-terminal residues of the peptide are largely unstructured, while in SDS micelles, these residues take on a well-defined compact conformation. Differences in helical residue side chain positioning between the two solvents were also found, with better agreement between the structures for the hydrophobic face than the hydrophilic face. A paramagnetic probe was used to investigate the position of the peptide within the SDS micelles and indicated that the peptide is located at the water interface with the hydrophobic face of the helix oriented inward, the hydrophilic face of the helix oriented outward, and the N-terminal residues even farther from the micelle center than those on the hydrophilic face of the alpha-helix. Interactions of basic residues of SP-B with anionic lipid headgroups are known to have an impact on function, and these studies demonstrate structural ramifications of such interactions via the differences observed between the peptide structures determined in HFIP and SDS.


    Organizational Affiliation

    Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X9, Canada. valerie@ physics.mun.ca




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Pulmonary surfactant-associated protein B
A
16Homo sapiensMutation(s): 0 
Gene Names: SFTPB (SFTP3)
Find proteins for P07988 (Homo sapiens)
Go to Gene View: SFTPB
Go to UniProtKB:  P07988
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 40 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with favorable non-bond energy 
  • Olderado: 1RG4 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-09-28
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance