Giant Amazonian fish pirarucu (Arapaima gigas): Its viscera as a source of thermostable trypsin

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• 作者：Augusto C.V. Freitas-Jú ; nior^a ; Helane M.S. Costa^a ; Marcelo Y. Icimoto^b ; Izaura Y. Hirata^b ; Marcelo Marcondes^b ; Luiz B. Carvalho Jr.^a ; Vitor Oliveira^b ; Ranilson S. Bezerra^a ; ^{ransoube@uol.com.br}
• 关键词：Arapaima gigas ; Air-breathing fish ; Fish processing waste ; Digestive enzymes ; Proteases ; Trypsin purification
• 刊名：Food Chemistry
• 出版年：2012
• 期刊代码：48_03088146
• 类别：abs
• 出版时间：15 August, 2012
• 卷：133
• 期：4
• 页码：1596-1602
• 文件大小：505 K

摘要

A trypsin was purified from pyloric caeca of pirarucu (Arapaima gigas). The effect of metal ions and protease inhibitors on its activity and its physicochemical and kinetic properties, as well its N-terminal sequence, were determined. A single band (28.0 kDa) was observed by SDS-PAGE. Optimum pH and temperature were 9.0 and 65 掳C, respectively. The enzyme was stable after incubation for 30 min in a wide pH range (6.0-11.5) and at 55 掳C. The kinetic parameters K_m, k_cat and k_cat/K_m were 0.47 卤 0.042 mM, 1.33 s^鈭? and 2.82 s^鈭? mM^鈭?, respectively, using BApNA as substrate. This activity was shown to be very sensitive to some metal ions, such as Fe²⁺, Hg²⁺, Zn²⁺, Al³⁺, Pb²⁺, and was highly inhibited by trypsin inhibitors. The trypsin N-terminal sequence IVGGYECPRNSVPYQ was found. The features of this alkaline peptidase suggest that it may have potential for industrial applications (e.g. food and detergent industries).