Nitrotyrosine: Difference between revisions
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[[Image:800px-Nitrotyrosine.png|right|thumb|3-Nitrotyrosine]] | [[Image:800px-Nitrotyrosine.png|right|thumb|3-Nitrotyrosine]] | ||
Nitrotyrosine<ref>[[User:Eric Martz]] wishes to thank [http://www.cancer.ucla.edu/index.aspx?page=645&recordid=338 Hermes J. Garbán] for bringing nitrotyrosine to his attention.</ref> results from the post-translational modification of the [[Amino_Acids|standard amino acid]] tyrosine. Reactive nitrogen compounds produced in inflammation are typically responsible. Nitrosylation of tyrosine tends to inactivate enzymes. | Nitrotyrosine<ref>[[User:Eric Martz]] wishes to thank [http://www.cancer.ucla.edu/index.aspx?page=645&recordid=338 Hermes J. Garbán] for bringing nitrotyrosine to his attention.</ref> results from the post-translational modification of the [[Amino_Acids|standard amino acid]] tyrosine. Reactive nitrogen compounds produced in inflammation are typically responsible. Nitrosylation of tyrosine tends to inactivate enzymes. | ||
In March, 2011, there are 13 entries in the [[PDB]] containing coordinates for 3-nitrotyrosine (meta-nitro-tyrosine), with the [[ | In March, 2011, there are 13 entries in the [[PDB]] containing coordinates for 3-nitrotyrosine (meta-nitro-tyrosine), with the [[Non-Standard_Residues|compound ID]] '''NIY'''. These include six sequence-distinct proteins, represented by ribonucleotide reductase [[2xof]] and [[2xap]], laccase [[3div]], Human Manganese Superoxide Dismutase [[2adp]], Human Glutathione Reductase [[1k4q]], and bovine Cu,Zn superoxide dismutase [[1sda]]. Not surprisingly, the NO<sub>2</sub> adduct, being very hydrophilic, is often on the surface of the protein. | ||
{{Clear}} | {{Clear}} | ||
<Structure size='450' frame='true' align='right' caption=' | <Structure size='450' frame='true' align='right' caption='' scene='Sandbox7_Eric_Martz/Cartoon/1' /> | ||
scene='Sandbox7_Eric_Martz/Cartoon/1' /> | One interesting case is Human <font color="#00c000">'''Manganese'''</font> Superoxide Dismutase, for which structures are available for the wild type [[2adq]], shown at right (<scene name='Sandbox7_Eric_Martz/Cartoon/1'>restore initial scene</scene>), and the nitrated form, [[2adp]]. In this structure, <font color="#00c000">'''Mn<sup>++</sup>'''</font> is <scene name='Sandbox7_Eric_Martz/Cartoon/2'>buried</scene>. The <font color="#00c000">'''Mn<sup>++</sup>'''</font> is | ||
One | |||
<scene name='Sandbox7_Eric_Martz/Mn_contacts/1'>caged</scene> by four histidine <font color="#3050F8">'''nitrogens'''</font>, one aspartate <font color="#ff0d0d">'''oxygen'''</font>, and one <font color="magenta">'''water'''</font>. Tyrosine 34 is nearby (5.2 Ångstroms), but not near enough to be interacting with the <font color="#00c000">'''Mn<sup>++</sup>'''</font> or its cage. | <scene name='Sandbox7_Eric_Martz/Mn_contacts/1'>caged</scene> by four histidine <font color="#3050F8">'''nitrogens'''</font>, one aspartate <font color="#ff0d0d">'''oxygen'''</font>, and one <font color="magenta">'''water'''</font>. Tyrosine 34 is nearby (5.2 Ångstroms), but not near enough to be interacting with the <font color="#00c000">'''Mn<sup>++</sup>'''</font> or its cage. | ||
<scene name='Sandbox7_Eric_Martz/Contacts_to_nitrotyrosine/1'>Nitrosylation of tyrosine 34</scene> extends it towards the <font color="#00c000">'''Mn<sup>++</sup>'''</font>. The partially negatively charged <font color="#ff0d0d">'''oxygens'''</font> in the NO<sub>2</sub> are 3.6-3.8 Å from the electron-hungry <font color="#00c000">'''Mn<sup>++</sup>'''</font>. <scene name='Sandbox7_Eric_Martz/Aligned_pre_and_post_nitro/2'>Nitrosylation pushes the tyrosine ring</scene> slightly farther from the <font color="#00c000">'''Mn<sup>++</sup>'''</font>, but causes no other significant conformational changes<ref>[[DeepView]] was used to align all atoms of the three Mn-coordinating histidines. In the resulting file [[Image:2adq-2adp-3hisaln.pdb]], 2adq is model 1, and 2adp is model 2.</ref>. The authors<ref>PMID: 16443160</ref> conclude | <scene name='Sandbox7_Eric_Martz/Contacts_to_nitrotyrosine/1'>Nitrosylation of tyrosine 34</scene> extends it towards the <font color="#00c000">'''Mn<sup>++</sup>'''</font>. The partially negatively charged <font color="#ff0d0d">'''oxygens'''</font> in the NO<sub>2</sub> are 3.6-3.8 Å from the electron-hungry <font color="#00c000">'''Mn<sup>++</sup>'''</font>. <scene name='Sandbox7_Eric_Martz/Aligned_pre_and_post_nitro/2'>Nitrosylation pushes the tyrosine ring</scene> slightly farther from the <font color="#00c000">'''Mn<sup>++</sup>'''</font>, but causes no other significant conformational changes<ref>[[DeepView]] was used to align all atoms of the three Mn-coordinating histidines. In the resulting file [[Image:2adq-2adp-3hisaln.pdb]], 2adq is model 1, and 2adp is model 2.</ref>. The authors<ref>PMID: 16443160</ref> conclude | ||