2MI1

Somatostatin-14 solution structure in 5% D-mannitol


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 10 
  • Conformers Submitted: 10 
  • Selection Criteria: all calculated structures submitted 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Elucidating the role of disulfide bond on amyloid formation and fibril reversibility of somatostatin-14: relevance to its storage and secretion.

Anoop, A.Ranganathan, S.Das Dhaked, B.Jha, N.N.Pratihar, S.Ghosh, S.Sahay, S.Kumar, S.Das, S.Kombrabail, M.Agarwal, K.Jacob, R.S.Singru, P.Bhaumik, P.Padinhateeri, R.Kumar, A.Maji, S.K.

(2014) J Biol Chem 289: 16884-16903

  • DOI: 10.1074/jbc.M114.548354
  • Primary Citation of Related Structures:  
    2MI1

  • PubMed Abstract: 
  • The storage of protein/peptide hormones within subcellular compartments and subsequent release are crucial for their native function, and hence these processes are intricately regulated in mammalian systems. Several peptide hormones were recently sug ...

    The storage of protein/peptide hormones within subcellular compartments and subsequent release are crucial for their native function, and hence these processes are intricately regulated in mammalian systems. Several peptide hormones were recently suggested to be stored as amyloids within endocrine secretory granules. This leads to an apparent paradox where storage requires formation of aggregates, and their function requires a supply of non-aggregated peptides on demand. The precise mechanism behind amyloid formation by these hormones and their subsequent release remain an open question. To address this, we examined aggregation and fibril reversibility of a cyclic peptide hormone somatostatin (SST)-14 using various techniques. After proving that SST gets stored as amyloid in vivo, we investigated the role of native structure in modulating its conformational dynamics and self-association by disrupting the disulfide bridge (Cys(3)-Cys(14)) in SST. Using two-dimensional NMR, we resolved the initial structure of somatostatin-14 leading to aggregation and further probed its conformational dynamics in silico. The perturbation in native structure (S-S cleavage) led to a significant increase in conformational flexibility and resulted in rapid amyloid formation. The fibrils formed by disulfide-reduced noncyclic SST possess greater resistance to denaturing conditions with decreased monomer releasing potency. MD simulations reveal marked differences in the intermolecular interactions in SST and noncyclic SST providing plausible explanation for differential aggregation and fibril reversibility observed experimentally in these structural variants. Our findings thus emphasize that subtle changes in the native structure of peptide hormone(s) could alter its conformational dynamics and amyloid formation, which might have significant implications on their reversible storage and secretion.


    Organizational Affiliation

    From the Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400 076, samirmaji@iitb.ac.in.



Macromolecules
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Somatostatin-14A14Homo sapiensMutation(s): 0 
Gene Names: SST
Find proteins for P61278 (Homo sapiens)
Explore P61278 
Go to UniProtKB:  P61278
NIH Common Fund Data Resources
PHAROS  P61278
Protein Feature View
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  • Reference Sequence
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 1
IDChainsNameType/Class2D Diagram3D Interactions
PRD_001216
Query on PRD_001216
ASomatostatin-14Cyclic peptide /  Inhibitor

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Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 10 
  • Conformers Submitted: 10 
  • Selection Criteria: all calculated structures submitted 
  • OLDERADO: 2MI1 Olderado

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-05-07
    Type: Initial release
  • Version 1.1: 2019-08-28
    Changes: Data collection, Database references, Derived calculations