Protease activity of enzyme extracts from tamarillo fruit and their specific hydrolysis of bovine caseins. (July 2018)

• Record Type: Journal Article
• Authors: Li, Zhao; Scott, Ken; Hemar, Yacine; Otter, Don
• Is Part Of: Food research international. Volume 109(2018)
• Page Start: 380
• Page End: 386
• Publication Date: 2018-07
• Subjects: Plant rennet -- Hydrolysis -- Bovine casein -- κ-casein -- Cleavage site; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2018.04.039
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: The characterisation of a serine protease isolated from tamarillo ( Solanum betaceum ) fruit and its milk casein hydrolysis activity were investigated. Compared with calf rennet, a crude extract from tamarillo exhibited wider caseinolytic activity on sodium caseinate. The purified protease was named "tamarillin" and revealed proteolytic activity toward purified α-, β- and κ-casein. Similar to calf rennet, tamarillin preferably hydrolysed κ-casein, but, unlike calf rennet, it also displayed high proteolytic activity toward both α- and β-casein. The major peptide generated from κ-casein by tamarillin was analysed by gel electrophoresis and liquid chromatography mass spectrometry to confirm its molecular mass as 14, 290 Da. The cleavage site was confirmed by in-gel tryptic digestion and time-of-flight mass spectrometry analysis to be at Asn123 -Thr124 . This was in contrast to the Phe105 -Met106 cleavage site of rennet hydrolysis. Graphical abstract: Highlights: Extent of casein hydrolysis was compared between rennet and tamarillo protease. Similar with rennet, tamarillin is preferable to hydrolysis κ-casein. A major peptide (14, 290 Da) was yield from tamarillin-induced κ-casein. A new protease hydrolysed cleavage site is investigated on κ-casein.