School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland 1143, New Zealand.
Food Res Int. 2018 Jul;109:380-386. doi: 10.1016/j.foodres.2018.04.039. Epub 2018 Apr 21.
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 Asn-Thr. This was in contrast to the Phe-Met cleavage site of rennet hydrolysis.
从番荔枝（Solanum betaceum）果实中分离得到的丝氨酸蛋白酶的特性及其对牛奶酪蛋白的水解活性进行了研究。与小牛凝乳酶相比，番荔枝粗提物对酪蛋白酸钠具有更广泛的酪蛋白水解活性。纯化的蛋白酶被命名为“tamarillin”，并对纯化的α-、β-和κ-酪蛋白表现出蛋白水解活性。与小牛凝乳酶相似，tamarillin 优先水解κ-酪蛋白，但与小牛凝乳酶不同的是，它对α-和β-酪蛋白也表现出很高的蛋白水解活性。用 tamarillin 从 κ-酪蛋白生成的主要肽通过凝胶电泳和液相色谱质谱分析确认其分子量为 14,290 Da。通过胶内胰蛋白酶消化和飞行时间质谱分析确认裂解位点为 Asn-Thr。这与凝乳酶水解的 Phe-Met 裂解位点形成对比。
