hollow protein crystals

bill lodi at dino.qci.bioch.bcm.tmc.edu
Thu Feb 9 18:31:41 EST 1995


 In article <9FEB95.21261996 at skyfox.usask.ca> matte at skyfox.usask.ca writes:
 >Hi,
 >	We have been growing protein crystals in
 >hanging drops, at various temperatures (ie. 4, 10
 >16, 21 C) from either salt or PEG solutions, but
 >they are invariably hollow in nature. It seems that
 >this is most likely due to the crystals growing too
 >fast once nucleation has taken place. I have read
 >that poisoning the mother liquor (with detergent,
 >etc) can sometmes help. Does anyone have any other
 >suggestions based on experience with this problem ?
 >

    About them growing too fast you are almost certainly
correct.  I believe this happens because the mother liquor
becomes locally depleted at the center of a rapidly growing
face.    In this case it looks like spontaneous nucleation
does not occur until the drop is very supersaturated-- you
might try microseeding a variety of starting conditions below
the pptant conc. where crystals are known to appear in order
to have a nucleus present at the outset of supersaturation.
Reducing the volume of the well solution or moving off of
ideal ph (along with seeding) may perhaps benefit.

good luck

W. E. Meador







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