View source for 1tz4

[[Image:1tz4.gif|left|200px]]

 {{Structure
|PDB= 1tz4 |SIZE=350|CAPTION= <scene name='initialview01'>1tz4</scene>
|SITE= 
|LIGAND= <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene>
|ACTIVITY= 
|GENE= 
|DOMAIN=
|RELATEDENTRY=[[1f8p|1F8P]], [[1ljv|1LJV]], [[1tz5|1TZ5]]
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tz4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tz4 OCA], [http://www.ebi.ac.uk/pdbsum/1tz4 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1tz4 RCSB]</span>
}}

'''[hPP19-23]-pNPY bound to DPC Micelles'''


==Overview==
Neuropeptide Y (NPY) and the pancreatic polypeptide (PP) are members of the neuropeptide Y family of hormones. They bind to the Y receptors with very different affinities: Whereas PP is highly selective for the Y(4) receptor, NPY displays highest affinites for Y(1), Y(2), and Y(5) receptor subtypes. Introducing the NPY segment 19-23 into PP leads to an increase in affinity at the Y(1) and Y(2) receptor subtypes whereas the exchange of this segment from PP into NPY leads to a large decrease in affinity at all receptor subtypes. PP displays a very stable structure in solution, with the N terminus being back-folded onto the C-terminal alpha-helix (the so-called PP-fold). The helix of NPY is less stable and the N terminus is freely diffusing in solution. The exchange of this segment, however, does not alter the PP-fold propensities of the chimeric peptides in solution. The structures of the phospholipid micelle-bound peptides serving to mimic the membrane-bound species display segregation into a more flexible N-terminal region and a well-defined alpha-helical region. The introduction of the [19-23]-pNPY segment into hPP leads to an N-terminal extension of the alpha-helix, now starting at Pro(14) instead of Met(17). In contrast, a truncated helix is observed in [(19)(-)(23)hPP]-pNPY, starting at Leu(17) instead of Ala(14). All peptides display moderate binding affinities to neutral membranes (K(assoc) in the range of 1.7 to 6.8 x 10(4) mol(-)(1) as determined by surface plasmon resonance) with the differences in binding being most probably related to the exchange of Arg-19 (pNPY) by Glu-23 (hPP). Differences in receptor binding properties between the chimeras and their parental peptides are therefore most likely due to changes in the conformation of the micelle-bound peptides.

==About this Structure==
1TZ4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa_and_homo_sapiens Sus scrofa and homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TZ4 OCA]. 

==Reference==
Strongly altered receptor binding properties in PP and NPY chimeras are accompanied by changes in structure and membrane binding., Lerch M, Kamimori H, Folkers G, Aguilar MI, Beck-Sickinger AG, Zerbe O, Biochemistry. 2005 Jun 28;44(25):9255-64. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15966750 15966750]
[[Category: Single protein]]
[[Category: Sus scrofa and homo sapiens]]
[[Category: Aguilar, M I.]]
[[Category: Beck-Sickinger, A G.]]
[[Category: Folkers, G.]]
[[Category: Kamimori, H.]]
[[Category: Lerch, M.]]
[[Category: Zerbe, O.]]
[[Category: npy-pp chimera]]

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