1nkf: Difference between revisions
m Protected "1nkf" [edit=sysop:move=sysop] |
No edit summary |
||
| Line 1: | Line 1: | ||
[[ | ==CALCIUM-BINDING PEPTIDE, NMR, 30 STRUCTURES== | ||
<StructureSection load='1nkf' size='340' side='right' caption='[[1nkf]], [[NMR_Ensembles_of_Models | 30 NMR models]]' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1nkf]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NKF OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1NKF FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=LA:LANTHANUM+(III)+ION'>LA</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1nkf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nkf OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1nkf RCSB], [http://www.ebi.ac.uk/pdbsum/1nkf PDBsum]</span></td></tr> | |||
<table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
A 12-residue peptide AcDKDGDGYISAAENH2 analogous to the third calcium-binding loop of calmodulin strongly coordinates lanthanide ions (K = 10(5) M-1). When metal saturated, the peptide adopts a very rigid structure, the same as in the native protein, with three last residues AAE fixed in the alpha-helical conformation. Therefore, the peptide provides an ideal helix nucleation site for peptide segments attached to its C terminus. NMR and CD investigations of peptide AcDKDGDGYISAAEAAAQNH2 presented in this paper show that residues A13-Q16 form an alpha-helix of very high stability when the La3+ ion is bound to the D1-E12 loop. In fact, the lowest estimates of the helix content in this segment give values of at least 80% at 1 degreesC and 70% at 25 degreesC. This finding is not compatible with existing helix-coil transition theories and helix propagation parameters, s, reported in the literature. We conclude, therefore, that the initial steps of helix propagation are characterized by much larger s values, whereas helix nucleation is even more unfavorable than is believed. In light of our findings, thermodynamics of the nascent alpha-helices is discussed. The problem of CD spectra of very short alpha-helices is also addressed. | |||
Alpha-helix nucleation by a calcium-binding peptide loop.,Siedlecka M, Goch G, Ejchart A, Sticht H, Bierzyski A Proc Natl Acad Sci U S A. 1999 Feb 2;96(3):903-8. PMID:9927666<ref>PMID:9927666</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
== | __TOC__ | ||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Ejchart, A.]] | [[Category: Ejchart, A.]] | ||
Revision as of 18:18, 28 September 2014
CALCIUM-BINDING PEPTIDE, NMR, 30 STRUCTURESCALCIUM-BINDING PEPTIDE, NMR, 30 STRUCTURES
Structural highlights
Publication Abstract from PubMedA 12-residue peptide AcDKDGDGYISAAENH2 analogous to the third calcium-binding loop of calmodulin strongly coordinates lanthanide ions (K = 10(5) M-1). When metal saturated, the peptide adopts a very rigid structure, the same as in the native protein, with three last residues AAE fixed in the alpha-helical conformation. Therefore, the peptide provides an ideal helix nucleation site for peptide segments attached to its C terminus. NMR and CD investigations of peptide AcDKDGDGYISAAEAAAQNH2 presented in this paper show that residues A13-Q16 form an alpha-helix of very high stability when the La3+ ion is bound to the D1-E12 loop. In fact, the lowest estimates of the helix content in this segment give values of at least 80% at 1 degreesC and 70% at 25 degreesC. This finding is not compatible with existing helix-coil transition theories and helix propagation parameters, s, reported in the literature. We conclude, therefore, that the initial steps of helix propagation are characterized by much larger s values, whereas helix nucleation is even more unfavorable than is believed. In light of our findings, thermodynamics of the nascent alpha-helices is discussed. The problem of CD spectra of very short alpha-helices is also addressed. Alpha-helix nucleation by a calcium-binding peptide loop.,Siedlecka M, Goch G, Ejchart A, Sticht H, Bierzyski A Proc Natl Acad Sci U S A. 1999 Feb 2;96(3):903-8. PMID:9927666[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
| ||||||||||||||||||