{"id":182,"date":"2017-10-25T01:34:49","date_gmt":"2017-10-24T23:34:49","guid":{"rendered":"https:\/\/fhedin.com\/?page_id=182"},"modified":"2018-07-25T09:26:51","modified_gmt":"2018-07-25T07:26:51","slug":"molecular-dynamics-investigation-of-human-haemoglobin-tetramer-stability","status":"publish","type":"page","link":"https:\/\/fhedin.com\/?page_id=182","title":{"rendered":"Molecular dynamics investigation of Human Haemoglobin Tetramer stability"},"content":{"rendered":"<p class=\"content-header__title content-header__title--long\" style=\"text-align: center;\"><strong><a href=\"https:\/\/elifesciences.org\/articles\/35560\" target=\"_blank\" rel=\"noopener\">Valid molecular dynamics simulations of human hemoglobin require a surprisingly large box size<\/a><\/strong><br \/>\n<strong>Krystel El Hage, Florent H\u00e9din, Prashant K Gupta, Markus Meuwly, Martin Karplus<\/strong><br \/>\n<strong>eLife 2018;7:e35560 DOI: 10.7554\/eLife.35560<\/strong><picture><\/picture><\/p>\n<p style=\"text-align: center;\"><a href=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/elife-35560-v1.pdf\" target=\"_blank\" rel=\"noopener\"><strong>Download PDF here<\/strong><\/a><\/p>\n<p style=\"text-align: center;\">\n<p>&nbsp;<\/p>\n<p>Recent molecular dynamics (MD) simulations of human hemoglobin (Hb) give results in disagreement with experiment. Although it is known that the unliganded (T<span id=\"MathJax-Element-1-Frame\" class=\"MathJax\" tabindex=\"0\" role=\"presentation\" data-mathml=\"&lt;math xmlns=&quot;http:\/\/www.w3.org\/1998\/Math\/MathML&quot; id=&quot;inf1&quot;&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow \/&gt;&lt;mn&gt;0&lt;\/mn&gt;&lt;\/msub&gt;&lt;\/mrow&gt;&lt;\/math&gt;\"><span id=\"inf1\" class=\"math\"><span id=\"MathJax-Span-2\" class=\"mrow\"><span id=\"MathJax-Span-3\" class=\"mrow\"><span id=\"MathJax-Span-4\" class=\"msub\"><span id=\"MathJax-Span-5\" class=\"mrow\"><\/span><span id=\"MathJax-Span-6\" class=\"mn\">0<\/span><\/span><\/span><\/span><\/span><\/span>) and liganded (R<span id=\"MathJax-Element-2-Frame\" class=\"MathJax\" tabindex=\"0\" role=\"presentation\" data-mathml=\"&lt;math xmlns=&quot;http:\/\/www.w3.org\/1998\/Math\/MathML&quot; id=&quot;inf2&quot;&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow \/&gt;&lt;mn&gt;4&lt;\/mn&gt;&lt;\/msub&gt;&lt;\/mrow&gt;&lt;\/math&gt;\"><span id=\"inf2\" class=\"math\"><span id=\"MathJax-Span-8\" class=\"mrow\"><span id=\"MathJax-Span-9\" class=\"mrow\"><span id=\"MathJax-Span-10\" class=\"msub\"><span id=\"MathJax-Span-11\" class=\"mrow\"><\/span><span id=\"MathJax-Span-12\" class=\"mn\">4<\/span><\/span><\/span><\/span><\/span><\/span>) tetramers are stable in solution, the published MD simulations of T<span id=\"MathJax-Element-3-Frame\" class=\"MathJax\" tabindex=\"0\" role=\"presentation\" data-mathml=\"&lt;math xmlns=&quot;http:\/\/www.w3.org\/1998\/Math\/MathML&quot; id=&quot;inf3&quot;&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow \/&gt;&lt;mn&gt;0&lt;\/mn&gt;&lt;\/msub&gt;&lt;\/mrow&gt;&lt;\/math&gt;\"><span id=\"inf3\" class=\"math\"><span id=\"MathJax-Span-14\" class=\"mrow\"><span id=\"MathJax-Span-15\" class=\"mrow\"><span id=\"MathJax-Span-16\" class=\"msub\"><span id=\"MathJax-Span-17\" class=\"mrow\"><\/span><span id=\"MathJax-Span-18\" class=\"mn\">0<\/span><\/span><\/span><\/span><\/span><\/span> undergo a rapid quaternary transition to an R-like structure. We show that T<span id=\"MathJax-Element-4-Frame\" class=\"MathJax\" tabindex=\"0\" role=\"presentation\" data-mathml=\"&lt;math xmlns=&quot;http:\/\/www.w3.org\/1998\/Math\/MathML&quot; id=&quot;inf4&quot;&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow \/&gt;&lt;mn&gt;0&lt;\/mn&gt;&lt;\/msub&gt;&lt;\/mrow&gt;&lt;\/math&gt;\"><span id=\"inf4\" class=\"math\"><span id=\"MathJax-Span-20\" class=\"mrow\"><span id=\"MathJax-Span-21\" class=\"mrow\"><span id=\"MathJax-Span-22\" class=\"msub\"><span id=\"MathJax-Span-23\" class=\"mrow\"><\/span><span id=\"MathJax-Span-24\" class=\"mn\">0<\/span><\/span><\/span><\/span><\/span><\/span> is stable only when the periodic solvent box contains ten times more water molecules than the standard size for such simulations. The results suggest that such a large box is required for the hydrophobic effect, which stabilizes the T<span id=\"MathJax-Element-5-Frame\" class=\"MathJax\" tabindex=\"0\" role=\"presentation\" data-mathml=\"&lt;math xmlns=&quot;http:\/\/www.w3.org\/1998\/Math\/MathML&quot; id=&quot;inf5&quot;&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow \/&gt;&lt;mn&gt;0&lt;\/mn&gt;&lt;\/msub&gt;&lt;\/mrow&gt;&lt;\/math&gt;\"><span id=\"inf5\" class=\"math\"><span id=\"MathJax-Span-26\" class=\"mrow\"><span id=\"MathJax-Span-27\" class=\"mrow\"><span id=\"MathJax-Span-28\" class=\"msub\"><span id=\"MathJax-Span-29\" class=\"mrow\"><\/span><span id=\"MathJax-Span-30\" class=\"mn\">0<\/span><\/span><\/span><\/span><\/span><\/span> tetramer, to be manifested. Even in the largest box, T<span id=\"MathJax-Element-6-Frame\" class=\"MathJax\" tabindex=\"0\" role=\"presentation\" data-mathml=\"&lt;math xmlns=&quot;http:\/\/www.w3.org\/1998\/Math\/MathML&quot; id=&quot;inf6&quot;&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow \/&gt;&lt;mn&gt;0&lt;\/mn&gt;&lt;\/msub&gt;&lt;\/mrow&gt;&lt;\/math&gt;\"><span id=\"inf6\" class=\"math\"><span id=\"MathJax-Span-32\" class=\"mrow\"><span id=\"MathJax-Span-33\" class=\"mrow\"><span id=\"MathJax-Span-34\" class=\"msub\"><span id=\"MathJax-Span-35\" class=\"mrow\"><\/span><span id=\"MathJax-Span-36\" class=\"mn\">0<\/span><\/span><\/span><\/span><\/span><\/span> is not stable unless His146 is protonated, providing an atomistic validation of the Perutz model. The possibility that extra large boxes are required to obtain meaningful results will have to be considered in evaluating existing and future simulations of a wide range of systems.<\/p>\n<p><a href=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/view_labels.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-238\" src=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/view_labels-1024x855.png\" alt=\"\" width=\"640\" height=\"534\" srcset=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/view_labels-1024x855.png 1024w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/view_labels-300x251.png 300w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/view_labels-768x641.png 768w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/view_labels.png 1195w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><a href=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/system.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-237\" src=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/system-1024x879.png\" alt=\"\" width=\"640\" height=\"549\" srcset=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/system-1024x879.png 1024w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/system-300x257.png 300w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/system-768x659.png 768w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/system.png 1184w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/p>\n<p><a href=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/hinge_scene.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-large wp-image-236\" src=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/hinge_scene-1024x720.png\" alt=\"\" width=\"640\" height=\"450\" srcset=\"https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/hinge_scene-1024x720.png 1024w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/hinge_scene-300x211.png 300w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/hinge_scene-768x540.png 768w, https:\/\/fhedin.com\/wp-content\/uploads\/2018\/07\/hinge_scene.png 1438w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Valid molecular dynamics simulations of human hemoglobin require a surprisingly large box size Krystel El Hage, Florent H\u00e9din, Prashant K Gupta, Markus Meuwly, Martin Karplus eLife 2018;7:e35560 DOI: 10.7554\/eLife.35560 Download PDF here &nbsp; Recent molecular dynamics (MD) simulations of human hemoglobin (Hb) give results in disagreement with experiment. Although it is known that the unliganded &#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":63,"menu_order":4,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-182","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/fhedin.com\/index.php?rest_route=\/wp\/v2\/pages\/182","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fhedin.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/fhedin.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/fhedin.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fhedin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=182"}],"version-history":[{"count":3,"href":"https:\/\/fhedin.com\/index.php?rest_route=\/wp\/v2\/pages\/182\/revisions"}],"predecessor-version":[{"id":239,"href":"https:\/\/fhedin.com\/index.php?rest_route=\/wp\/v2\/pages\/182\/revisions\/239"}],"up":[{"embeddable":true,"href":"https:\/\/fhedin.com\/index.php?rest_route=\/wp\/v2\/pages\/63"}],"wp:attachment":[{"href":"https:\/\/fhedin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=182"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}