|WikiProject Chemistry||(Rated Start-class, Low-importance)|
Does is stike anyone else that de Duve's explanation is not satisfactory? Keep in mind that the use of ATP involves several steps of enzyme catalysations(if that's a word). How would thioester be useful without such enzymes, and does it need them at all, or can it self-hydrolysize? --Alkafett 20:26, 18 Apr 2005 (UTC)
Using IUPAC nomenclature - esters are named alcohol then carboxylic acid (classically) - which would make R-S-(C=0)-R (discussed in this article) a thiolester not a thioester. Thionoester is the correct term for an R-O-(C=S)-R species - deriving its name from thione functional group ( C=S ).
I know I have seen examples in the literature (chemical and biochemical) with both thioester and thiolester being used to mean R-S-(C=0)-R - so I can understand the confusion. but i feel that this article should be alterred for clarification ----arthuc01 5.27 7th Jan 2007 (GMT)
thioester via activated acyl
A thioester, if it stably exists, is obviously matching self-dehydration to self-hydrolysis. But in de Duve's scenario for a pre-ATP energy economy, as well as with coenzyme A's need to hang onto a fatty acid, then release it, one must wonder how a single thiol can have its nucleophilicity switched on demand between two values, flipping the equilibrium as circumstances require. I have long thought that pantetheine's amides were spaced advantageously for an intramolecular charge-relay system. Merely by rotating a few of its bonds - with near-zero net free-energy change - the molecule could show a great range of pKa at the thiol. Some years ago I sought to test this by substituting simple acyl or sulfonyl moieties for the pantoyl group in pantetheine to see if the thiol's acidity responded. Since I was a lousy chemist, I never got pure products, and so confirmed nothing. Thus I believe this does not violate Wikipedia's rule against original research! Meanwhile, an online search for "pantetheine charge-relay" yields nothing germane. Clearly, though, pantetheine has some special aptitude for its office. Jahutter (talk) 22:48, 2 August 2012 (UTC)