Abstract

The enzymic properties of protease in the Pleurotus cornucopiae(Per.) Rolland were investigated. The $K_m$ value was 0.45 mM when hippuryl-L-phenylalanine was used as a substrate. This enzyme showed substrate specificity hydrolyzing the peptide bond of glycyl-L-phenylalanine. This enzyme was inhibited by L-lysine, diazoacetyl-DL-norleucine methyl ester(DAN), 1,2-epoxy-(p-nitrophenoxy) propane(EPNP) and EDTA, also was inhibited by anion as ${SO_3}^{-2}$, ${SO_4}^{-2}$ and ${HPO_4}^{-2}$ but increased with ${NO_2}^{-1}$ ion. The L-cysteine was found to be competitive inhibitor and its $K_i$ value was determined to be 2.4 mM by Dixon plot.

흰느타리버섯(Pleurotus cornucopiae (Per.) Rolland)의 protease를 분리 정제하여 그 성질을 조사하였다. Hippuryl-L-phenylalanine 기질에 대한 이 효소의 $K_m$ 값은 0.45 mM 이었고, glycyl-L-phenylalanine의 펩티드 결합을 분해시키는 특이성을 보였다. L-Cysteine, L-Lysine, DAN, EPNP, EDTA, ${SO_3}^{-2}$, ${SO_4}^{-2}$, 및 ${HPO_4}^{-2}$은 효소활성을 저해하였고, ${NO_2}^{-1}$은 활성을 증가시켰다. L-Cysteine은 경쟁적 방해제로 작용하였고, 그것의 $K_i$값은 2.4 mM 이었다. $pK_a$값은 4.4였다.

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