Purification and biochemical characterization of a novel thermostable protease from the oyster mushroom Pleurotus sajor-caju strain CTM10057 with industrial interest

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]

ISSN: 1472-6750