1soc
From Proteopedia
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|PDB= 1soc |SIZE=350|CAPTION= <scene name='initialview01'>1soc</scene> | |PDB= 1soc |SIZE=350|CAPTION= <scene name='initialview01'>1soc</scene> | ||
|SITE= | |SITE= | ||
| - | |LIGAND= | + | |LIGAND= <scene name='pdbligand=DPN:D-PHENYLALANINE'>DPN</scene>, <scene name='pdbligand=DTR:D-TRYPTOPHAN'>DTR</scene>, <scene name='pdbligand=THO:REDUCED+THREONINE'>THO</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[2soc|2SOC]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1soc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1soc OCA], [http://www.ebi.ac.uk/pdbsum/1soc PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1soc RCSB]</span> | ||
}} | }} | ||
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[[Category: sandostatin]] | [[Category: sandostatin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:44:50 2008'' |
Revision as of 20:44, 30 March 2008
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| Ligands: | , , | ||||||
| Related: | 2SOC
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
NMR STUDY OF THE BACKBONE CONFORMATIONAL EQUILIBRIA OF SANDOSTATIN, MINIMIZED AVERAGE BETA-SHEET STRUCTURE
Overview
This paper reports a detailed conformational analysis by 1H NMR (DMSO-d6, 300 K) and molecular modeling of the octapeptide D-Phe1-Cys2-Phe3-D-Trp4-Lys5-Thr6-Cys7+ ++-Thr8-ol (disulfide bridged) known as sandostatin (or SMS 201-995 or octreotide) with both somatostatin-like and opioid-like bioactivities. This is the initial report on sandostatin showing that attempts to explain all NMR data using a single average conformation reveal several important inconsistencies including severe violations of mutually exclusive backbone-to-backbone NOEs. The inconsistencies are solved by assuming an equilibrium between antiparallel beta-sheet structures and conformations in which the C-terminal residues form a 3(10) helix-like fold (helical ensemble). This conformational equilibrium is consistent with previous X-ray diffraction investigations which show that sandostatin can adopt both the beta-sheet and the 3(10) helix-like secondary structure folds. In addition, indications of a conformational equilibrium between beta-sheet and helical structures are also found in solvent systems different from DMSO-d6 and for other highly bioactive analogs of sandostatin. In these cases a proper multiconformational NMR refinement is important in order to avoid conformational averaging artifacts. Finally, using the known models for somatostatin-like and opioid-like bioactivities of sandostatin analogs, the present investigation shows the potentials of the proposed structures for the design of novel sandostatin-based conformationally restricted peptidomimetics. These analogs are expected to refine the pharmacophore models for sandostatin bioactivities.
About this Structure
1SOC is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Multiconformational NMR analysis of sandostatin (octreotide): equilibrium between beta-sheet and partially helical structures., Melacini G, Zhu Q, Goodman M, Biochemistry. 1997 Feb 11;36(6):1233-41. PMID:9063871
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