Bovine trypsin works well. You can buy it pretty cheap from Sigma and it crystallizes without further purification, within a week. Crystals diffract to 1.1-1.3 A and are quite robust to handling and soaking. Conditions that I used are described in this ref: http://www.pnas.org/content/103/18/6835.long
I would avoid commercial preps of porcine elastase; I messed around with that one around 10 years ago using many reported crystallization conditions and suppliers but never got crystals. Evette S. Radisky, Ph.D. Assistant Professor Mayo Clinic Cancer Center Griffin Cancer Research Building, Rm 310 4500 San Pablo Road Jacksonville, FL 32224 (904) 953-6372 -----Original Message----- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of David Roberts Sent: Monday, February 04, 2013 11:03 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] need some suggestions for crystallization So, I know I say this every time I post on this board, but here it goes again. I'm at an undergrad only school, and every 2 years I teach a class in protein crystallography. This year I'm being super ambitious, and I'm going to take a class of 16 to the synchrotron for data collection. It's just an 8 hour thing, to show them the entire process. I'm hoping that we can collect 5-6 good data sets while there. I would like them to grow their own crystals, and go collect data. Then we'd come back and actually do a molecular replacement (pretty easy/standard really). Just to get a feel for how it works. The protein I do research on is not one that I would push on this, as the crystals are hard to grow, they are very soft, and the data just isn't the best (resolution issues). I do have a few that will work on my proteins, but I was thinking of having others in the class grow up classic proteins for data collection. Obviously lysozyme is one, but I was wondering what other standard bulletproof conditions are out there. Can you all suggest some protein crystallization conditions (along with cryo conditions) for some commercially available proteins? I'm looking to get 6-8 different ones (and we'll just take them and see how it goes). I wouldn't mind knowing unit cell parameters as well (just a citation works, I can have them figure it out). I have about 7 weeks to get everything grown and frozen and ready to go. Any help would be greatly appreciated. It always amazes me how helpful this group is. Thank you very much. Dave