Kim Misook, Hamilton Susan E, Guddat Luke W, Overall Christopher M
School of Molecular and Microbial Sciences, The University of Queensland, St Lucia, Australia.
Biochim Biophys Acta. 2007 Dec;1770(12):1627-35. doi: 10.1016/j.bbagen.2007.08.003. Epub 2007 Aug 24.
Two cysteine proteases, GP2 and GP3, have been isolated from ginger rhizomes (Zingiber officinale). GP2 is virtually identical to a previously identified ginger protease GPII [K.H. Choi, and R.A. Laursen, Amino-acid sequence and glycan structures of cysteine proteases with proline specificity from ginger rhizome Zingiber officinale, Eur. J. Biochem. 267 (2000) 1516-1526.], and cleaves native type I collagen at multiple discrete sites, which are in the interior of the triple helical region of this molecule. In reaction with proline-containing peptides GP2 shows preference for Pro in the P2 position, and at least 10-fold higher efficiency of hydrolysis than papain. Comparison of models of GP2 and GP3 with the crystal structure of papain shows that the three enzymes have different S2 pocket structures. The S2 pocket in GP2 and GP3 is half the size of that of papain. GP2 is the only reported plant cysteine protease with a demonstrated ability to hydrolyse native collagen. The results support a role for ginger proteases as an alternative to papain, in commercial applications such as meat tenderization, where collagen is the target substrate.
从姜根茎（姜科植物姜）中分离出了两种半胱氨酸蛋白酶，即GP2和GP3。GP2实际上与先前鉴定出的生姜蛋白酶GPII相同[K.H. Choi和R.A. Laursen，姜根茎（姜科植物姜）中具有脯氨酸特异性的半胱氨酸蛋白酶的氨基酸序列和聚糖结构，《欧洲生物化学杂志》267（2000）1516 - 1526]，它在多个离散位点切割天然I型胶原蛋白，这些位点位于该分子三螺旋区域的内部。在与含脯氨酸的肽反应时，GP2对P2位置的脯氨酸表现出偏好，水解效率比木瓜蛋白酶至少高10倍。将GP2和GP3的模型与木瓜蛋白酶的晶体结构进行比较表明，这三种酶具有不同的S2口袋结构。GP2和GP3中的S2口袋大小是木瓜蛋白酶的一半。GP2是唯一报道的具有水解天然胶原蛋白能力的植物半胱氨酸蛋白酶。这些结果支持了生姜蛋白酶在诸如肉类嫩化等商业应用中作为木瓜蛋白酶替代品的作用，在这些应用中胶原蛋白是目标底物。
