1do7: Difference between revisions

Revision as of 13:18, 21 February 2008

CARBONMONOXY-MYOGLOBIN (MUTANT L29W) REBINDING STRUCTURE AFTER PHOTOLYSIS AT T< 180K

OverviewOverview

Myoglobin, a small globular haem protein that binds gaseous ligands such as O2, CO and NO reversibly at the haem iron, serves as a model for studying structural and dynamic aspects of protein reactions. Time-resolved spectroscopic measurements after photodissociation of the ligand revealed a complex ligand-binding reaction with multiple kinetic intermediates, resulting from protein relaxation and movements of the ligand within the protein. To observe the structural changes induced by ligand dissociation, we have carried out X-ray crystallographic investigations of carbon monoxy-myoglobin (MbCO mutant L29W) crystals illuminated below and above 180 K, complemented by time-resolved infrared spectroscopy of CO rebinding. Here we show that below 180 K photodissociated ligands migrate to specific sites within an internal cavity--the distal haem pocket--of an essentially immobilized, frozen protein, from where they subsequently rebind by thermally activated barrier crossing. Upon photodissociation above 180 K, ligands escape from the distal pocket, aided by protein fluctuations that transiently open exit channels. We recover most of the ligands in a cavity on the opposite side of the haem group.

About this StructureAbout this Structure

1DO7 is a Single protein structure of sequence from Physeter catodon with , and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

Ligand binding and conformational motions in myoglobin., Ostermann A, Waschipky R, Parak FG, Nienhaus GU, Nature. 2000 Mar 9;404(6774):205-8. PMID:10724176

Page seeded by OCA on Thu Feb 21 12:18:42 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
-[[Image:1do7.jpg|left|200px]]<br /><applet load="1do7" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1do7.jpg|left|200px]]<br /><applet load="1do7" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1do7, resolution 1.85&Aring;" />
 '''CARBONMONOXY-MYOGLOBIN (MUTANT L29W) REBINDING STRUCTURE AFTER PHOTOLYSIS AT T< 180K'''<br />
 ==Overview==
-Myoglobin, a small globular haem protein that binds gaseous ligands such, as O2, CO and NO reversibly at the haem iron, serves as a model for, studying structural and dynamic aspects of protein reactions., Time-resolved spectroscopic measurements after photodissociation of the, ligand revealed a complex ligand-binding reaction with multiple kinetic, intermediates, resulting from protein relaxation and movements of the, ligand within the protein. To observe the structural changes induced by, ligand dissociation, we have carried out X-ray crystallographic, investigations of carbon monoxy-myoglobin (MbCO mutant L29W) crystals, illuminated below and above 180 K, complemented by time-resolved infrared, spectroscopy of CO rebinding. Here we show that below 180 K, photodissociated ligands migrate to specific sites within an internal, cavity--the distal haem pocket--of an essentially immobilized, frozen, protein, from where they subsequently rebind by thermally activated, barrier crossing. Upon photodissociation above 180 K, ligands escape from, the distal pocket, aided by protein fluctuations that transiently open, exit channels. We recover most of the ligands in a cavity on the opposite, side of the haem group.
+Myoglobin, a small globular haem protein that binds gaseous ligands such as O2, CO and NO reversibly at the haem iron, serves as a model for studying structural and dynamic aspects of protein reactions. Time-resolved spectroscopic measurements after photodissociation of the ligand revealed a complex ligand-binding reaction with multiple kinetic intermediates, resulting from protein relaxation and movements of the ligand within the protein. To observe the structural changes induced by ligand dissociation, we have carried out X-ray crystallographic investigations of carbon monoxy-myoglobin (MbCO mutant L29W) crystals illuminated below and above 180 K, complemented by time-resolved infrared spectroscopy of CO rebinding. Here we show that below 180 K photodissociated ligands migrate to specific sites within an internal cavity--the distal haem pocket--of an essentially immobilized, frozen protein, from where they subsequently rebind by thermally activated barrier crossing. Upon photodissociation above 180 K, ligands escape from the distal pocket, aided by protein fluctuations that transiently open exit channels. We recover most of the ligands in a cavity on the opposite side of the haem group.
 ==About this Structure==
-DO7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Physeter_catodon Physeter catodon] with SO4, HEM and CMO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1DO7 OCA].
+DO7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Physeter_catodon Physeter catodon] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=CMO:'>CMO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DO7 OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Physeter catodon]]
 [[Category: Single protein]]
-[[Category: Nienhaus, G.U.]]
+[[Category: Nienhaus, G U.]]
 [[Category: Ostermann, A.]]
-[[Category: Parak, F.G.]]
+[[Category: Parak, F G.]]
 [[Category: Waschipky, R.]]
 [[Category: CMO]]
@@ Line 25: / Line 25: @@
 [[Category: respiratory protein]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 13:26:27 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:18:42 2008''