Biochemical and enzymatic properties of a fibrinolytic enzyme from Pleurotus eryngii cultivated under solid-state conditions using corn cob

Biochemical and enzymatic properties of a fibrinolytic enzyme purified from Pleurotus eryngii cultivated under solid-state conditions using corn cob as energy source were investigated. The molecular mass of the enzyme was estimated to be 14 kDa by SDS–PAGE. The enzyme exhibited the highest activity (28.96 mol/min/mg) for the substrate tosyl-Gly-Pro-Lys-p-nitroanilide. Km and Vmax values were 0.18 mM and 53.5 U/ml, respectively. The enzyme was completely inhibited by 1.0 mM phenylmethylsulfonyl fluoride (PMSF). The N-terminal sequence was A-M-D-S-Q-T-D-A-S-Y-G-LA-N-D. This sequence exhibited a high degree of similarity to the N-terminal sequences of the subtilisin-like serine proteases. The enzyme was very stable at pH 4.0–6.0 with an optimum pH 5.0 at 40 °C. The enzyme rapidly hydrolyzed the A α-chain of fibrinogen within 5 min of incubation, followed by the B β-chain after 10 min. The fibrinolytic enzyme from P. eryngii cultivated under solid-state conditions using corn cob could be potentially exploited in thrombolytic therapy.