Odd mutate issue on 859

[gitwut]

I've run into an unusual problem with 859. I decided to use the attached design as a starting point and changed all of the mutable segments to Isoleucines. I've been running various mutate scripts for one or two days (not sure exactly) and there seem to be very few if any changes–certainly not what I would expect. Could whatever is going on also be related to why mutate takes so long? Note the 15 iterations and 43 minutes elapsed for mutate–the only change seems to be one phenylalanine although I noticed one or two other segments that changed but reverted.<p>
This solution was shared via "Upload to Scientists" as: gw-859 Mutate example

[brow42]

I have noticed that if you attempt mutate on all-alanine or all-isoleucine, mutate is excruciatingly slow and makes few changes. After I mutate by hand to have a mix, mutate runs more normally.

[gitwut]

I haven't had the issue using all Alanines on the starting position (I swtiched as soon as I posted the feedback). There are still many more hydrophobes on the exterior than I would expect but the overall mix is not too bad. Unfortunately, it still doesn't look like the design will score well.