EXTRACTION AND CHARACTERIZATION OF SEA CUCUMBER Isostichopus fuscus PROTEASES, COLLECTED AT THE GULF OF CALIFORNIA, MEXICO

作者：Hernandez Samano A C; Guzman Garcia X; Garcia Barrientos R; Ascencio Valle F; Sierra Beltran A; Vallejo Cordoba B; Gonzalez Cordova A F; Torres Llanez M J; Guerrero Legarreta I^*

来源：Revista Mexicana de Ingenieria Quimica, 2015, 14(1): 35-47.

• sea cucumber
• Isostichopus fuscus
• ventral muscle
• proteases
• enzyme characterization

Enzyme extracts obtained from I. fuscus ventral muscle were studied. Peak activity was observed at pH 2, 6, and 8, and 50-60 degrees C, whereas maximum enzymatic stability occurred at pH 2 to 6 (except pH 3) and 0 to 40 degrees C. More than 74% residual activity was retained after heating at 70 degrees C and 80 degrees C for 1 h, confirming the presence of heat-resistant enzymes. The extracts also retained 59% initial activity after 21-day storage at 4-5 degrees C. Hg2+ increased the proteolytic activity in 16%, whereas Cu2+ and Mn2+ caused partial inhibition, suggesting the presence of cysteine- and metallo- proteases. Extracts were inhibited by pepstatin A, beta-mercaptoethanol and EDTA, confirming the predominance of aspartyl-, cystein-, and metallo-, proteases. Four proteins were identified by SDS-PAGE (180.6, 114.5, 91.7 and 52.9 kDa). Zymograms on casein confirmed the presence of proteolytic enzymes. After purification by anion exchange chromatography a 49 kDa protease, possible metalloprotease, was detected. Mass spectrometry of the partially purified protein showed homology with trypsin and chain E, leech-derived tryptase inhibitor trypsin complex (LDTI). Due that no homology was found with any previously described metalloproteases, the presence of a novel enzyme is suggested.

• 出版日期2015-4