Table 2. Design matrix for optimization of papain purity and total activity using CCD.

Run	CPEG (%, w/w)	Csalt (%, w/w)	pH	Papain purity* (%)	Total activity of PEG phase (nkat)
1	0 (16)	−2 (10)	0 (6)	92.05±1.8	18.57±0.2
2	1 (18)	1 (16)	1 (7)	97.45±1.9	2.94±0.1
3	−1 (14)	1 (16)	−1 (5)	92.33±0.9	20.67±0.2
4	1 (18)	−1 (12)	1 (7)	97.42±1.0	12.30±0.2
5	1 (18)	−1 (12)	−1 (5)	89.42±0.9	22.74±0.7
6	−1 (14)	1 (16)	1 (7)	97.86±2.0	8.24±0.2
7	0 (16)	0 (14)	0 (6)	98.11±1.0	18.41±0.2
8	0 (16)	2 (18)	0 (6)	100.00±1.0	3.32±0.1
9	0 (16)	0 (14)	2 (8)	96.75±1.9	1.27±0.1
10	−1 (14)	−1 (12)	−1 (5)	87.59±1.8	23.10±0.5
11	0 (16)	0 (14)	−2 (4)	82.85±0.8	24.62±0.7
12	0 (16)	0 (14)	0 (6)	96.01±1.0	17.24±0.2
13	0 (16)	0 (14)	0 (6)	98.64±1.0	16.46±0.3
14	−2 (12)	0 (14)	0 (6)	96.35±1.9	18.95±0.2
15	2 (20)	0 (14)	0 (6)	97.95±0.5	12.13±0.1
16	0 (16)	0 (14)	0 (6)	98.14±1.0	18.16±0.7
17	−1 (14)	−1 (12)	1 (7)	96.16±0.5	13.36±0.1
18	1 (18)	1 (16)	−1 (5)	96.22±1.0	17.77±0.2
19	0 (16)	0 (14)	0 (6)	96.45±1.9	17.53±0.2
20	0 (16)	0 (14)	0 (6)	97.53±1.0	17.72±0.1

Actual variables are given in parentheses.

*Determined by FPLC.