College of Food Science, Northeast Agricultural University, Harbin, China.
Department of Food Science and Agricultural Chemistry, McGill University, Sainte-Anne-de-Bellevue, QC, Canada.
J Sci Food Agric. 2021 Sep;101(12):5016-5027. doi: 10.1002/jsfa.11146. Epub 2021 Mar 13.
Microbial protease can interact with meat protein in fermented meat products at a certain pH and temperature. To investigate the effects of various pH values and temperatures on the structural characteristics of Lactobacillus fermentum R6 protease, which was isolated from Harbin dry sausages, spectroscopy techniques and molecular dynamics were utilized to evaluate structural changes.
The protease exhibited a stable spatial structure at pH 7 and 40 °C, and the extension of the protease structure was also promoted. Although the structure of the protease could be changed or destroyed by pH 8 and 70 °C, it was mainly determined by the changes of secondary and tertiary structures such as α-helix, β-sheet, β-turn and random coil. In addition, carbonyl vibration, -NH vibration, C-H stretching vibration and disulphide bonds were present in L. fermentum R6 protease under various pH and temperature conditions. Molecular docking showed that the protease can interact with myosin light chain, myosin heavy chain, actin and myoglobin.
The protease can maintain stable structure and interact with meat protein, which reflected certain application prospects in the fermentation of Harbin dry sausages. © 2021 Society of Chemical Industry.
微生物蛋白酶可以在一定的 pH 值和温度下与发酵肉制品中的肉蛋白相互作用。为了研究不同 pH 值和温度对从哈尔滨干肠中分离出的植物乳杆菌 R6 蛋白酶结构特性的影响，利用光谱技术和分子动力学对结构变化进行了评估。
该蛋白酶在 pH7 和 40°C 时表现出稳定的空间结构，并且促进了蛋白酶结构的伸展。虽然 pH8 和 70°C 可以改变或破坏蛋白酶的结构，但主要是由二级和三级结构如α-螺旋、β-折叠、β-转角和无规卷曲的变化决定的。此外，在各种 pH 值和温度条件下，植物乳杆菌 R6 蛋白酶都存在羰基振动、-NH 振动、C-H 伸缩振动和二硫键。分子对接表明，蛋白酶可以与肌球蛋白轻链、肌球蛋白重链、肌动蛋白和肌红蛋白相互作用。
该蛋白酶能够保持稳定的结构并与肉蛋白相互作用，这反映了其在哈尔滨干肠发酵过程中的一定应用前景。 © 2021 英国化学学会。
