Preparation of Antioxidant Peptides from Salmon Byproducts with Bacterial Extracellular Proteases.
Preparation of Antioxidant Peptides from Salmon Byproducts with Bacterial Extracellular Proteases.
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用细菌胞外蛋白酶从鲑鱼副产品中制备抗氧化肽。
DOI：
10.3390/md15010004
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发表时间：
2017-01-11
期刊：
影响因子：
5.4
通讯作者：
He H
中科院分区：
文献类型：
--
作者：
Wu R;Chen L;Liu D;Huang J;Zhang J;Xiao X;Lei M;Chen Y;He H
采用发酵法制备了6株海洋细菌和7株陆生细菌的细菌胞外蛋白酶。通过底物浸泡酶谱分析了水解酶，并将其分别用于水解鱼皮副产物中的胶原蛋白和肌肉蛋白。胶原蛋白比肌肉蛋白更容易降解，但其抗氧化能力一般较弱。以假交替单胞菌的粗酶为原料制备肌肉蛋白水解物。在DPPH和羟基自由基清除实验中，SQN1的抗氧化活性最强(74.06%±1.14%和69.71%±1.97%)，但在Fe2+螯合实验中表现不佳。经超滤、阳离子交换层析、尺寸排斥层析等步骤纯化得到的抗氧化组分U2-S2-I在DPPH、清除羟基自由基活性实验(IC50分别为0.263±0.018 mg/mL和0.512±0.055 mg/mL)、氧自由基吸收能力实验(1.960±0.381 mmol.te/g)中均表现出较强的抗氧化活性。最终纯化的组份U2-S2-I具有保护DNA免受羟基自由基损伤的能力，其效果与原始水解物相似。这表明U2-S2-I可能是该水解物的主要活性部位。本研究证明细菌胞外蛋白水解酶可用于三文鱼副产物的水解。与胶原蛋白相比，肌肉蛋白是制备抗氧化肽的理想酶底物。
Bacterial extracellular proteases from six strains of marine bacteria and seven strains of terrestrial bacteria were prepared through fermentation. Proteases were analyzed through substrate immersing zymography and used to hydrolyze the collagen and muscle proteins from a salmon skin byproduct, respectively. Collagen could be degraded much more easily than muscle protein, but it commonly showed weaker antioxidant capability. The hydrolysate of muscle proteins was prepared with crude enzymes from Pseudoalteromonas sp. SQN1 displayed the strongest activity of antioxidant in DPPH and hydroxyl radical scavenging assays (74.06% ± 1.14% and 69.71% ± 1.97%), but did not perform well in Fe2+ chelating assay. The antioxidant fractions were purified through ultrafiltration, cation exchange chromatography, and size exclusion chromatography gradually, and the final purified fraction U2-S2-I displayed strong activity of antioxidant in DPPH, hydroxyl radical scavenging assays (IC50 = 0.263 ± 0.018 mg/mL and 0.512 ± 0.055 mg/mL), and oxygen radical absorption capability assay (1.960 ± 0.381 mmol·TE/g). The final purified fraction U2-S2-I possessed the capability to protect plasmid DNA against the damage of hydroxyl radical and its effect was similar to that of the original hydrolysis product. It indicated that U2-S2-I might be the major active fraction of the hydrolysate. This study proved that bacterial extracellular proteases could be utilized in hydrolysis of a salmon byproduct. Compared with collagen, muscle proteins was an ideal material used as an enzymatic substrate to prepare antioxidant peptides.