https://en.formulasearchengine.com/index.php?action=history&feed=atom&title=Time_dilation_of_moving_particlesTime dilation of moving particles - Revision history2026-04-21T06:10:45ZRevision history for this page on the wikiMediaWiki 1.43.0-wmf.28https://en.formulasearchengine.com/index.php?title=Time_dilation_of_moving_particles&diff=11171&oldid=preven>D.H: /* Atmospheric tests */2014-01-01T10:19:25Z<p><span class="autocomment">Atmospheric tests</span></p>
<p><b>New page</b></p><div>[[Solution|Solutes]] are defined as '''kosmotropic''' if they contribute to the stability and structure of water-water interactions. Kosmotropes cause water molecules to favorably interact, which also stabilizes intermolecular interactions in [[macromolecules]] such as proteins.<br />
<br />
==Ionic Kosmotropes==<br />
Ionic kosmotropes tend to be small or have high charge density. Some ionic kosmotropes are [[sulfate]], phosphate, [[magnesium]](2+), [[lithium]](1+), [[zinc]] (2+) and [[aluminium]] (+3). Large ions or ions with low charge density (such as [[bromide]], [[iodide]], [[potassium]](1+), [[caesium]](1+)) instead act as [[Chaotropic agent|chaotropes]].<br />
<br />
A scale can be established if one refers to the [[Franz Hofmeister|Hofmeister]] series or looks up the [[Gibbs free energy|free energy]] of [[Hydration reaction|hydration]] (<math>\Delta G_{\rm hydr}</math>) of the salts. The more negative <math>\Delta G_{\rm hydr}</math>, the more kosmotropic the salt.<br />
<br />
==Applications==<br />
[[Ammonium sulfate]] is the traditional kosmotropic salt for the salting out of protein from an aqueous solution. Kosmotropes are used to prevent protein aggregation in pharmaceutical preparation and at various stage of protein extraction and purification. They act by stabilizing native intramolecular protein interactions, thus out-competing the intermolecular interactions that lead to aggregation.<br />
<br />
==Nonionic Kosmotropes==<br />
Nonionic kosmotropes have no net charge but are very soluble and become very hydrated. Carbohydrates such as [[trehalose]] and [[glucose]] as well as [[proline]] and [[Tert-Butanol|''tert''-butanol]] are kosmotropes.<br />
<br />
==See also==<br />
*[[Chaotropic agent]] and [[Guanidinium chloride]]<br />
*[[Protein precipitation]], on aluminium sulfate "salting out"<br />
<br />
==External links==<br />
* [http://www.lsbu.ac.uk/water/kosmos.html Kosmotropes and Chaotropes] (from [http://www.lsbu.ac.uk/water/index2.html Water Structure and Behavior])<br />
* {{cite journal|pmid=12554139|year=2003|last1=Polson|first1=C|last2=Sarkar|first2=P|last3=Incledon|first3=B|last4=Raguvaran|first4=V|last5=Grant|first5=R|title=Optimization of protein precipitation based upon effectiveness of protein removal and ionization effect in liquid chromatography-tandem mass spectrometry|volume=785|issue=2|pages=263–275|journal=Journal of chromatography. B, Analytical technologies in the biomedical and life sciences|doi=10.1016/S1570-0232(02)00914-5}}<br />
<br />
[[Category:Chemical compounds]]<br />
<br />
<br />
{{chem-stub}}</div>en>D.H