1ppt
From Proteopedia
(New page: 200px<br /><applet load="1ppt" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ppt, resolution 1.37Å" /> '''X-RAY ANALYSIS (1.4-...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1ppt.gif|left|200px]]<br /><applet load="1ppt" size=" | + | [[Image:1ppt.gif|left|200px]]<br /><applet load="1ppt" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ppt, resolution 1.37Å" /> | caption="1ppt, resolution 1.37Å" /> | ||
'''X-RAY ANALYSIS (1.4-ANGSTROMS RESOLUTION) OF AVIAN PANCREATIC POLYPEPTIDE. SMALL GLOBULAR PROTEIN HORMONE'''<br /> | '''X-RAY ANALYSIS (1.4-ANGSTROMS RESOLUTION) OF AVIAN PANCREATIC POLYPEPTIDE. SMALL GLOBULAR PROTEIN HORMONE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of avian pancreatic polypeptide (aPP), a 36-residue | + | The crystal structure of avian pancreatic polypeptide (aPP), a 36-residue polypeptide with some hormonal properties, has been determined by using single isomorphous replacement and anomalous scattering to 2.1-A resolution. The phases were extended to 1.4-A resolution by using a modified tangent formula. The molecule contains two regions of secondary structure-an extended polyproline-like helix (residues 1-8) and an alpha-helix (residues 14-31)-that run roughly antiparallel. The packing together of nonpolar groups from these regions gives the molecule a hydrophobic core in spite of its small size. The aPP molecules form a symmetrical dimer in the crystal stabilized principally by interlocking of nonpolar groups from the alpha-helices. The aPP dimers are crosslinked by coordination of Zn(2+); three aPP molecules contribute ligands to each zinc. The coordination geometry is a distorted trigonal bipyramid. The properties of the aPP molecule in solution are consistent with expectations based on the crystal structure. The aPP molecule has several general features in common with the pancreatic hormones insulin and glucagon. All three hormones have complex mechanisms for self-association. Like insulin, aPP seems to have a stable monomeric structure but its biological activity seems to depend on the more flexible COOH-terminal region analogous to the flexible NH(2)-terminal region of glucagon. |
==About this Structure== | ==About this Structure== | ||
| - | 1PPT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Meleagris_gallopavo Meleagris gallopavo] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1PPT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Meleagris_gallopavo Meleagris gallopavo] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PPT OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Meleagris gallopavo]] | [[Category: Meleagris gallopavo]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Blundell, T | + | [[Category: Blundell, T L.]] |
| - | [[Category: Pitts, J | + | [[Category: Pitts, J E.]] |
| - | [[Category: Tickle, I | + | [[Category: Tickle, I J.]] |
| - | [[Category: Wood, S | + | [[Category: Wood, S P.]] |
[[Category: ZN]] | [[Category: ZN]] | ||
[[Category: pancreatic hormone]] | [[Category: pancreatic hormone]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:31:23 2008'' |
Revision as of 12:31, 21 February 2008
|
X-RAY ANALYSIS (1.4-ANGSTROMS RESOLUTION) OF AVIAN PANCREATIC POLYPEPTIDE. SMALL GLOBULAR PROTEIN HORMONE
Overview
The crystal structure of avian pancreatic polypeptide (aPP), a 36-residue polypeptide with some hormonal properties, has been determined by using single isomorphous replacement and anomalous scattering to 2.1-A resolution. The phases were extended to 1.4-A resolution by using a modified tangent formula. The molecule contains two regions of secondary structure-an extended polyproline-like helix (residues 1-8) and an alpha-helix (residues 14-31)-that run roughly antiparallel. The packing together of nonpolar groups from these regions gives the molecule a hydrophobic core in spite of its small size. The aPP molecules form a symmetrical dimer in the crystal stabilized principally by interlocking of nonpolar groups from the alpha-helices. The aPP dimers are crosslinked by coordination of Zn(2+); three aPP molecules contribute ligands to each zinc. The coordination geometry is a distorted trigonal bipyramid. The properties of the aPP molecule in solution are consistent with expectations based on the crystal structure. The aPP molecule has several general features in common with the pancreatic hormones insulin and glucagon. All three hormones have complex mechanisms for self-association. Like insulin, aPP seems to have a stable monomeric structure but its biological activity seems to depend on the more flexible COOH-terminal region analogous to the flexible NH(2)-terminal region of glucagon.
About this Structure
1PPT is a Single protein structure of sequence from Meleagris gallopavo with as ligand. Full crystallographic information is available from OCA.
Reference
X-ray analysis (1. 4-A resolution) of avian pancreatic polypeptide: Small globular protein hormone., Blundell TL, Pitts JE, Tickle IJ, Wood SP, Wu CW, Proc Natl Acad Sci U S A. 1981 Jul;78(7):4175-4179. PMID:16593056
Page seeded by OCA on Thu Feb 21 14:31:23 2008
