Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
Fish Protein Laboratory, Suzuhiro Kamaboko Honten Co., Ltd., Odawara, Kanagawa 250-0862, Japan.
J Agric Food Chem. 2020 Nov 11;68(45):12683-12691. doi: 10.1021/acs.jafc.0c04427. Epub 2020 Oct 28.
Surimi gel is a commonly found gelled product in Japan. Disintegration of the surimi gel is mainly caused by proteolytic degradation of the myosin heavy chain (MHC) under an inappropriate heating process. Many studies have reported the decrease in MHC in the disintegrated surimi gel but the mechanistic details of this degradation remain unclear. This study employed peptidomic analysis of disintegrated surimi gels from deep-sea bonefish to reveal the MHC cleavage causing gel disintegration. More peptides derived from an MHC rod were found in the disintegrated surimi gels than in the integrated gel. Most MHC peptides were derived from the Src homology 3 domain or near the skip residues. The results of the terminome analysis suggest that the catalytic type of the proteases is responsible for light meromyosin cleavage activated at ∼35 °C. These results showed the temperature-dependent cleavage of the MHC rod, causing disintegration of the surimi gel.
鱼糜凝胶是日本常见的凝胶产品。鱼糜凝胶的解体主要是由于肌球蛋白重链（MHC）在不合适的加热过程中发生蛋白水解降解。许多研究报道了解体鱼糜凝胶中 MHC 的减少，但这种降解的机制细节尚不清楚。本研究采用肽组学分析深海鱼骨鱼解体鱼糜凝胶，揭示导致凝胶解体的 MHC 切割。在解体的鱼糜凝胶中发现了比完整凝胶更多的 MHC 棒衍生肽。大多数 MHC 肽来自 Src 同源性 3 结构域或靠近跳跃残基。末端分析的结果表明，蛋白酶的催化类型负责在 ∼35°C 下激活轻肌球蛋白的切割。这些结果表明 MHC 棒的温度依赖性切割导致了鱼糜凝胶的解体。
