ASAP protocol: Crystallization of Enterovirus D68 3C protease (PDB code 8CNX)
Peter Marples, Lizbé Koekemoer, Daren Fearon, ryan Lithgo
Abstract
The crystallization protocol and buffer conditions used to obtain Enterovirus D68 3C protease crystals suitable for XChem fragment screening. The crystal structure was depostited to RCSB PDB with code 8CNX.
Steps
Equipment needed
Formulatrix Rock Imager (or incubator of choice)
SPT mosquito
P100 multi-channel pipette
SwissCI 3 lens plate
Crystallization experiment
Protein and buffer requirements:
32µL``1millimolar (mM) Sample
2.88mL
16µL Sample seeds, dilution 1:100 000
Crystallisation screen composition:
0.1 M Tris-HCl (pH 8.14)
0.2 M Ammonium acetate
25% w/v PEG 3350
Stock solutions used:
1 M Tris-HCl adjusted to pH 8.14 with HCl
1 M Ammonium acetate
50% w/v PEG 3350
Prepare seed stock: seed stock:
1: 100 000 dilution Sample seeds
Dispense 30µL into SwissCI 3 lens plate reservoir wells using a 100 µl multi-channel pipette.
Dispense 100nL``1millimolar (mM) Sample to each lens using the SPT mosquito.
Dispense 200nL to each lens using the SPT mosquito.
Dispense 50nL to each lens using the SPT mosquito.
Drop ratio: 1:2:05 ratio (100 nl Sample : 200 nl reservoir solution: 50 nl seeds)
Final drop volume: 350 nl
Incubate at 20°C for 24h 0m 0s in Formulatrix Rock Imager.
Imaging Schedule : The first images are taken after 12 h and the imaging schedule follows a Fibonacci sequence of days for further collections.
Crystal form after ~12 h.