Table 1.

Flow sheet purification of SPPS from Pleurotus sajor-caju strain CTM10057

Purification step a	Total activity (units) b × 104	Total protein (mg) b.c	Specific activity (U/mg of protein) b	Activity recovery rate (%)	Purification factor (fold)
Crude extract	525 ± 13	590 ± 14	8823	100	1
Heat treatment (20 min at 80 °C)	430 ± 10	240 ± 6	17,917	82	2
(NH4)2SO4 fractionation (35–55%)-dialysis	375 ± 9	160 ± 4	23,437	71.4	3
FPLC (UNO Q-6)	152 ± 3	40 ± 1	38,000	28.5	4.3
HPLC (ZORBAX PSM 300 HPSEC)	79 ± 2	10 ± 0.5	79,000	15	9

^a Experiments were conducted three times and ± standard errors are reported

^b One unit (U) of protease activity was defined as the amount of enzyme required to release 1 μg tyrosine per minute under the experimental conditions used

^c Amounts of protein were estimated by the method of Bradford [30]