Hydrogen Bonding Regulates the Monomeric Nonradiative Decay of Adenine in DNA Strands†

Abstract

<a style="widows: 2; text-transform: none; background-color: #ffffff; text-indent: 0px; margin: 0px; outline-width: 0px; letter-spacing: normal; font: 12px/10px Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, sans-serif; white-space: normal; orphans: 2; float: left; color: #007e8a; clear: left; vertical-align: baseline; word-spacing: 0px; text-decoration: underline; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px; padding: 0px" href="http://onlinelibrary.wiley.com/store/10.1002/anie.201008146/asset/image_m/mcontent.gif?v=1&amp;s=0eea570c0df3e8e5c64578896e98077e4c7b79d9" title="Link to full-size graphical abstract" class="figZoom"><img style="background-color: transparent; margin: 0.5em 1.5em 1.5em 0px; outline-width: 0px; font-size: 12px; vertical-align: bottom; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px; padding: 0px" src="http://onlinelibrary.wiley.com/store/10.1002/anie.201008146/asset/image_n/ncontent.gif?v=1&amp;s=3df5269c411f8fb5a63b9ab76c0e45d86fab750b" alt="Thumbnail image of graphical abstract" title="Thumbnail image of graphical abstract" /></a> <div class="para" style="widows: 2; text-transform: none; background-color: #ffffff; text-indent: 0px; margin: 0px; outline-width: 0px; letter-spacing: normal; font: 12px/10px Arial, 'Lucida Grande', Geneva, Verdana, Helvetica, sans-serif; white-space: normal; orphans: 2; color: #000000; clear: none; vertical-align: baseline; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px; padding: 0px"><p style="line-height: 1.5em; background-color: transparent; margin: 0px 0px 1em; outline-width: 0px; font-size: 1.2em; vertical-align: baseline; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px; padding: 0px"><strong style="background-color: transparent; margin: 0px; outline-width: 0px; font-size: 12px; vertical-align: baseline; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px; padding: 0px">Distinct fates</strong>: For adenine in (dA)<sub style="padding-bottom: 0px; line-height: 0.7em; background-color: transparent; margin: 0px; padding-left: 0.2em; outline-width: 0px; padding-right: 0px; white-space: nowrap; font-size: 0.8em; vertical-align: sub; padding-top: 0px; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px">10</sub>, the internal conversion to the ground state is dominated by an S<sub style="padding-bottom: 0px; line-height: 0.7em; background-color: transparent; margin: 0px; padding-left: 0.2em; outline-width: 0px; padding-right: 0px; white-space: nowrap; font-size: 0.8em; vertical-align: sub; padding-top: 0px; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px">0</sub>/S<sub style="padding-bottom: 0px; line-height: 0.7em; background-color: transparent; margin: 0px; padding-left: 0.2em; outline-width: 0px; padding-right: 0px; white-space: nowrap; font-size: 0.8em; vertical-align: sub; padding-top: 0px; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px">1</sub><span class="Apple-converted-space">&nbsp;</span>conical intersection with a strong out-of-plane deformation of the amino group (left). In (dA)<sub style="padding-bottom: 0px; line-height: 0.7em; background-color: transparent; margin: 0px; padding-left: 0.2em; outline-width: 0px; padding-right: 0px; white-space: nowrap; font-size: 0.8em; vertical-align: sub; padding-top: 0px; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px">10</sub>&sdot;(dT)<sub style="padding-bottom: 0px; line-height: 0.7em; background-color: transparent; margin: 0px; padding-left: 0.2em; outline-width: 0px; padding-right: 0px; white-space: nowrap; font-size: 0.8em; vertical-align: sub; padding-top: 0px; border-image: initial; background-origin: initial; background-clip: initial; border-width: 0px">10</sub>, this channel is suppressed by adenine&ndash;thymine hydrogen bonding (right). The excited-state lifetimes of adenine are computed to be ten times longer in DNA strands than in vacuo or in water.</p></div