Purification and characterisation of trypsins from the pyloric caeca of mandarin fish (Siniperca chuatsi)

Purification and characteristics of trypsin from masu salmon (Oncorhynchus masou) cultured in fresh-water

“…1). The relative molecular mass of the masu salmon trypsin was similar to those of other fish trypsins (Simpson and Haard 1984;Asgeirsson et al 1989;Kishimura et al 2005Kishimura et al , 2006aKishimura et al , b, c, 2007Kishimura et al , 2008Klomklao et al 2006aKlomklao et al , b, 2007a) except for those of rainbow trout (25,700 Da) (Kristjansson 1991), mandarin fish (21,000 and 21,500 Da) (Lu et al 2008), Atlantic bonito (29,000 Da) (Klomklao et al 2007b), and blufish (28,000 Da) (Klomklao et al 2007c).…”

“…TAME was hydrolyzed effectively by the enzyme in the pH range from 7.0 to 9.0, with an optimum around pH 8.5. The optimum pH of the masu salmon trypsin was the same as those of other fish trypsins (Hjelmeland and Raa 1982;Simpson and Haard 1984;Martinez et al 1988;Asgeirsson et al 1989;Castillo-Yanez et al 2005;Kishimura et al 2005Kishimura et al , 2006aKishimura et al , b, c, 2007Kishimura et al , 2008Klomklao et al 2006aKlomklao et al , b, 2007aLu et al 2008), but lower than those of rainbow trout (pH 9-10) (Kristjansson 1991) and bluefish (pH 9.5) (Klomklao et al 2007c). The pH stability of the masu salmon trypsin is shown in Fig.…”

“…On the other hand, there is little information regarding trypsin from fresh-water fish (Kristjansson 1991;Lu et al 2008). Masu salmon is one of the Salmonidae, and it inhabits the Asian side of the northern Pacific Ocean (Kato 1991).…”

Partial purification and characterization of alkaline proteases from the Black Sea anchovy(Engraulis encrasicholus) digestive tract

“…These results show that the partially purified enzyme from anchovy digestive tract exhibit protease characteristics. Our results are similar with other data in the study of Martinez et al (1988), Kristjansson (1991), Bougatef et al (2007), Shi et al (2007) and Lu et al (2008) enzyme was not affected by β-mercaptoethanol. Based on the results, metallo-protease inhibitor EDTA, which chelates the metals ions required for the enzyme, partially inhibited enzyme activity by 19%, indicating the importance of some metal ions in enzyme stabilization.…”

“…The trypsin from hoki fish (Shi et al, 2007) and Sardinella viscera (Khaled et al, 2008) were found to be inactive when heated at 60°C for 30 min. According to Lu et al (2008), trypsin of mandarin fish lost its activity when heated at 50°C for 30 min. Thermal stabilities of fish proteolytic enzymes vary with species and substrate differences, in addition to incubation conditions.…”