Interactive Crystallomic - Molecules: Nucleation, Aggregation and Crystallization - page 230

Table 1. A Summary of the Crystallization Trials of BK Virus-like Particles a

A1
Virus, 2 mg/ml
1% (w/v)
PEG20 000
50 mM Tris, pH 7.5
[ C p ] * [ C v ]

A2
Virus, 4 mg/ml
1.25% (w/v)
PEG20 000
50 mM Tris, pH 7.5
[ C p ] * [ C v ]

A3
Virus 6, mg/ml
1.6% (w/v)
PEG20 000
50 mM Tris, pH 7.5
[ C p ] * [ C v ]

A4
Virus, 8 mg/ml
5.0% (w/v)
PEG20 000
50 mM Tris, pH 7.5
[ C p ] * [ C v ]

A5
Virus, 8 mg/ml
2.5% (w/v)
PEG20 000
50 mM Tris, pH 7.5
[ C p ] * [ C v ]

A6
Virus, 10 mg/ml
2% (w/v)
PEG20 000
50 mM Tris, pH 7.5
[ C p ] * [ C v ] = 2 = 5 = 9.6 = 40 = 20 = 20

Outcome scores:
0 (0 day)
0 (10 days)
0 (1 month)
0 (3 months)

Outcome scores:
0
0
0
0

Outcome scores:
0
0
0
0

Outcome scores:
0.5
3
3
3

Outcome scores:
0
0
7
7

Outcome scores:
0
0
9
9

Note : The scoring of the outcomes of crystallization (Sedzik 1994) of each drop was as follows:
0 - drop was clear, without precipitate; 0.5 - very weak amorphous precipitate; 3 - very strong amorphous precipitate; 7 - several (shower) microcrystals of
~0.05 mm; 9 - single crystals of ∼0.1 mm, and without any amorphous precipitate.
a The crystallization trials were performed in the following order: A1-A5. Experiment A4 gave an immediate precipitate when the virus solution (8 mg/ml)
was mixed with the reservoir at a concentration of 5% (w/v) of polyethylene glycol, which has a molecular weight of 20 000. Therefore, in experiment
A5, the concentration of the precipitate was lowered to 2.5% (w/v). In all the drops, the buffer was 50 mM Tris, pH 7.5. The dishes were disturbed only three
times during the three-month period of the experiments. Crystals were noticed in drop A5 during the second evaluation check, one month after the experiment
was set up. The dishes were kept in darkness at room temperature (21-23°C). C p — concentration of precipitate; C v — concentration of virus.