Characterization of a Fibrinolytic Serine Protease from an Edible Mushroom, Albatrellus confluens

A fibrinolytic serine protease was purified from the fruiting bodies of an edible mushroom, Albatrellus confluens. The enzyme had a molecular mass of 30086.41 Da, as measured by MALDI-TOF mass spectrometry. The N-terminal amino acid sequence of the enzyme was Glu-Thr-Val-Thr-Glu-Thr-Thr-Ala -Pro-Trp-Gly-Leu-Ser-Arg-Ile. It displayed optimal activity at $50^{\circ}C$ and within a pH range of $8.0{\sim}10.0$, suggesting that the enzyme is an alkaline protease. The enzyme was stable up to $30^{\circ}C$. The enzyme displayed a strong substrate specificity for the synthetic peptide, N-Suc-Ala-Ala-Pro-Phe pNA. The enzyme activity was completely inhibited by addition of PMSF, indicating that the enzyme is a serine protease. No inhibition was observed following addition of E-64, pepstatin, or EDTA. The activity of the purified enzyme was decreased in the presence $Fe^{2+}$ or $Co^{2+}$, and the enzyme was completely inhibited by addition of $Hg^{2+}$. From these results, we propose that Albatrellus confluens could be used for biofunctional foods development and has potential therapeutic value for the treatment of vascular diseases.

다발구멍장이버섯으로부터 분리한 혈전용해 세린분해효소의 특성 연구

3단계를 거처 식용 가능한 다발구멍장이버섯으로부터 분리한 혈전용해효소의 비활성은 30.49 U/mg이었으며, MALDI-TOF/MS로부터 분자량이 30086.41 Da이었다. 일차 아미노산 구조는 Glu-Thr-Val-Thr-Glu-Thr-Thr-Ala-Pro-Trp-Gly-Leu-Ser-Arg-Ile으로 밝혀졌으며, pH 8.0에서 pH 10.0의 넓은 범위에서 큰 활성을 나타내는 alkaline protease로, 최적온도는 $50^{\circ}C$이며, $30^{\circ}C$까지는 대체로 열에 안정한 효소였다. 이 효소는 합성 기질 N-Suc-Ala-Ala-Pro-Phe pNA을 강하게 분해하였으며, $Hg^{2+}$ 금속이온의 첨가로 효소 활성이 완전히 사라졌다. 효소저해제인 PMSF의 첨가로 혈전용해활성이 사라지는 결과로부터 serine 분해효소임을 알 수 있었다.