[snarks_when_bored]

Wake-up ping...

[PatrickHenry]

Evolution Ping The List-O-Links

A conservative, pro-evolution science list, now with over 320 names. See the list's explanation, then FReepmail to be added or dropped. To assist beginners: But it's "just a theory", Evo-Troll's Toolkit, and How to argue against a scientific theory.

[bkepley]

Anybody who reads this article and feels no astonishment is either stupid or not paying attention.

Call me stupid if you want (I think ignorant is the right word, stupid) but what am I supposed to be astonished about, the experiement or the results?

[grey_whiskers]

Hey, Cool!

Two further points:

1. Are we sure the mass of the glass bead being tugged along did not affect the mechanics?

2. I'd been playing in my mind with just such a mechanism: often people trying to get protein structure from ab initio sequences take some molecular dynamics program and let the protein "relax" to a preferred structure. But of course this isn't how proteins are constructed in vivo: if you add one peptide at a time, the lowest energy configuration of an intermediate fragment might be different than the preferred configuration of that same subsequence in the full chain. What effects would there be on predicted protein folding starting from one peptide at a time? Do we have enough CPU time to model this properly?

Extra credit: Are all proteins build "one peptide at a time" or are significant sub-assemblies built first and then put together using enzymes? I dunno? Any biochemists here have any ideas?

Cheers!

Full Disclosure: Thanks, Snarks!

[tophat9000]

With all do respect to unzip the bonds one at a time up the ladder is the most logical thing, it is the lowest energy required (less force to pop one bond at time then two bond at a time, less force to pop one bond on the open end that to pop one bond in between two connect bonds)

And in the experiment glued a glass bead on one end of the strands in effect adding an unnatural load the "unbonding" had to drag from one end and you have in effect altered the normal condition (maybe it unzips from both end to the middle normally)

Bottom line it's no more amazing for mechanical bonds to upzip one bond at a time then a zipper to unzip one tooth at a time... all you need in a little force to start the unzipping (say a chemical reaction creating a electrify charge?)