1b0q
From Proteopedia
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|PDB= 1b0q |SIZE=350|CAPTION= <scene name='initialview01'>1b0q</scene> | |PDB= 1b0q |SIZE=350|CAPTION= <scene name='initialview01'>1b0q</scene> | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=DPN:D-PHENYLALANINE'>DPN</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene>, <scene name='pdbligand=RE:RHENIUM'>RE</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1b0q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1b0q OCA], [http://www.ebi.ac.uk/pdbsum/1b0q PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1b0q RCSB]</span> | ||
}} | }} | ||
| Line 26: | Line 29: | ||
[[Category: Quinn, T P.]] | [[Category: Quinn, T P.]] | ||
[[Category: Wang, N.]] | [[Category: Wang, N.]] | ||
| - | [[Category: ACE]] | ||
| - | [[Category: NH2]] | ||
| - | [[Category: RE]] | ||
[[Category: alpha melanocyte stimulating hormone]] | [[Category: alpha melanocyte stimulating hormone]] | ||
[[Category: peptide]] | [[Category: peptide]] | ||
[[Category: rhenium technetium]] | [[Category: rhenium technetium]] | ||
| - | ''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 18:51:20 2008'' |
Revision as of 15:51, 30 March 2008
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| Ligands: | , , , | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
DITHIOL ALPHA MELANOTROPIN PEPTIDE CYCLIZED VIA RHENIUM METAL COORDINATION
Overview
alpha-Melanocyte stimulating hormone (alpha-MSH) analogs, cyclized through site-specific rhenium (Re) and technetium (Tc) metal coordination, were structurally characterized and analyzed for their abilities to bind alpha-MSH receptors present on melanoma cells and in tumor-bearing mice. Results from receptor-binding assays conducted with B16 F1 murine melanoma cells indicated that receptor-binding affinity was reduced to approximately 1% of its original levels after Re incorporation into the cyclic Cys4,10, D-Phe7-alpha-MSH4-13 analog. Structural analysis of the Re-peptide complex showed that the disulfide bond of the original peptide was replaced by thiolate-metal-thiolate cyclization. A comparison of the metal-bound and metal-free structures indicated that metal complexation dramatically altered the structure of the receptor-binding core sequence. Redesign of the metal binding site resulted in a second-generation Re-peptide complex (ReCCMSH) that displayed a receptor-binding affinity of 2.9 nM, 25-fold higher than the initial Re-alpha-MSH analog. Characterization of the second-generation Re-peptide complex indicated that the peptide was still cyclized through Re coordination, but the structure of the receptor-binding sequence was no longer constrained. The corresponding 99mTc- and 188ReCCMSH complexes were synthesized and shown to be stable in phosphate-buffered saline and to challenges from diethylenetriaminepentaacetic acid (DTPA) and free cysteine. In vivo, the 99mTcCCMSH complex exhibited significant tumor uptake and retention and was effective in imaging melanoma in a murine-tumor model system. Cyclization of alpha-MSH analogs via 99mTc and 188Re yields chemically stable and biologically active molecules with potential melanoma-imaging and therapeutic properties.
About this Structure
1B0Q is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Design and characterization of alpha-melanotropin peptide analogs cyclized through rhenium and technetium metal coordination., Giblin MF, Wang N, Hoffman TJ, Jurisson SS, Quinn TP, Proc Natl Acad Sci U S A. 1998 Oct 27;95(22):12814-8. PMID:9788997
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