Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
Biosci Biotechnol Biochem. 2022 Apr 21;86(5):635-645. doi: 10.1093/bbb/zbac020.
This study compared ice recrystallization behaviors of frozen dessert model systems containing type I antifreeze protein (AFP I), type III antifreeze protein (AFP III), and antifreeze glycoprotein (AFGP) at -10 °C. Specifically, effects of AF(G)P concentration and heat treatment (95 °C for 10 min) were examined. The concentration dependence of the ice recrystallization rate constant reasonably well fit a sigmoidal function: the fitting procedure was proposed, along with cooperative coefficient α, and a new index of AF(G)P ice recrystallization inhibition (IRI) activity (C50). After 95 °C heat treatment for 10 min, AFP III lost its ice crystal recrystallization inhibitory activity the most: AFP I was less affected; AFGP was almost entirely unaffected. These different thermal treatment effects might reflect a lower degree of protein aggregation because of hydrophobic interaction after heat treatment or might reflect the simplicity and flexibility of the higher order structures of AFP I and AFGP.
本研究比较了含有 I 型抗冻蛋白 (AFP I)、III 型抗冻蛋白 (AFP III) 和抗冻糖蛋白 (AFGP) 的冷冻甜点模型系统在-10°C 下的冰晶重结晶行为。具体而言，考察了 AF(G)P 浓度和热处理（95°C 10 分钟）的影响。冰晶重结晶速率常数的浓度依赖性很好地符合 S 形函数：提出了拟合过程，以及协同系数α和抗冻蛋白（AF(G)P）冰晶重结晶抑制（IRI）活性的新指标（C50）。经 95°C 热处理 10 分钟后，AFP III 失去了冰晶重结晶抑制活性，AFP I 的影响较小，AFGP 几乎完全不受影响。这些不同的热处理效果可能反映了由于热后疏水性相互作用导致的蛋白质聚集程度较低，或者可能反映了 AFP I 和 AFGP 较高阶结构的简单性和灵活性。
