View source for 4twv


==Horse heart myoglobin mutant (K45E/K63E/K96E) with Zn-deuteroporphyrin IX==
<StructureSection load='4twv' size='340' side='right'caption='[[4twv]], [[Resolution|resolution]] 1.06&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4twv]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Equus_caballus Equus caballus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4TWV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4TWV FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.06&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZND:ZINC+(II)+DEUTEROPORPHYRIN+IX'>ZND</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4twv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4twv OCA], [https://pdbe.org/4twv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4twv RCSB], [https://www.ebi.ac.uk/pdbsum/4twv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4twv ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MYG_HORSE MYG_HORSE] Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
We report rapid photoinitiated intracomplex electron transfer (ET) within a "charge-disproportionated" myoglobin (Mb) dimer with greatly enhanced affinity. Two mutually supportive Brownian Dynamics (BD) interface redesign strategies, one a new "heme-filtering" approach, were employed to "break the symmetry" of a Mb homodimer by pairing Mb constructs with complementary highly positive and highly negative net surface charges, introduced through D/E --&gt; K and K --&gt; E mutations, respectively. BD simulations using a previously developed positive mutant, Mb(+6) = Mb(D44K/D60K/E85K), led to construction of the complementary negative mutant Mb(-6) = Mb(K45E, K63E, K95E). Simulations predict the pair will form a well-defined complex comprising a tight ensemble of conformations with nearly parallel hemes, at a metal-metal distance approximately 18-19 A. Upon expression and X-ray characterization of the partners, BD predictions were verified through ET photocycle measurements enabled by Zn-deuteroporphyrin substitution, forming the [ZnMb(-6), Fe(3+)Mb(+6)] complex. Triplet ET quenching shows charge disproportionation increases the binding constant by no less than approximately 5 orders of magnitude relative to wild-type Mb values. All progress curves for charge separation (CS) and charge recombination (CR) are reproduced by a generalized kinetic model for the interprotein ET photocycle. The intracomplex ET rate constants for both CS and CR are increased by over 5 orders of magnitude, and their viscosity independence is indicative of true interprotein ET, rather than dynamic gating as seen in previous studies. The complex displays an unprecedented timecourse for CR of the CS intermediate I. After a laser flash, I forms through photoinduced CS, accumulates to a maximum concentration, then dies away through CR. However, before completely disappearing, I reappears without another flash and reaches a second maximum before disappearing completely.

Charge-Disproportionation Symmetry Breaking Creates a Heterodimeric Myoglobin Complex with Enhanced Affinity and Rapid Intracomplex Electron Transfer.,Trana EN, Nocek JM, Woude JV, Span I, Smith SM, Rosenzweig AC, Hoffman BM J Am Chem Soc. 2016 Sep 28;138(38):12615-28. doi: 10.1021/jacs.6b07672. Epub 2016, Sep 20. PMID:27646786<ref>PMID:27646786</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4twv" style="background-color:#fffaf0;"></div>

==See Also==
*[[Myoglobin 3D structures|Myoglobin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Equus caballus]]
[[Category: Large Structures]]
[[Category: Rosenzweig AC]]
[[Category: Span I]]