missing disulphide bond in Turkey puzzle
|Opened on:||Tuesday, December 14, 2010 - 16:52|
|Last modified:||Tuesday, August 23, 2011 - 19:54|
From the guide it looks as if there should be a 4th disulphide bond between the cysteines at segments #6 and #127. But it isn't present at the start of the puzzle like the other three bonds. I have been unable to coax this bond to form by folding, and I suspect that it can't be done and the disulphide bonds need to be present at the start of the puzzle. I also suspect that a really good guide match won't be possible since the absence of this bond throws out the forces. Is this an oversight in the puzzle presentation, or is it to do with the unfolded state? I checked and #6 and #127 are some way apart in the partly unfolded starting position, and you wouldn't be able to get the bond in place at that time, so maybe that was the problem: could only set up three of the bonds at the start. Would like to know what the status of disulphide bonds is. It would be nice in future if we had some way of setting up a disulphide bond once we have the cysteines in the right alignment, but I can understand if that is too difficult to program correctly in FoldIt. I put a lot of effort into this puzzle and got the alignment of the other three bonding cysteine pairs pretty well, so it is unfortunate that I may not be able to complete the quartet!