Identification and characterization of multifunctional cationic peptides from traditional Japanese fermented soybean Natto extracts

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Identification of cationic peptides derived from low protein rice by-products and evaluation of their multifunctional activities

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Immunomodulation by hydrolysates and peptides derived from milk proteins

Milk protein‐derived peptides have shown immunomodulatory properties either singly or in a mixture. However, information on the behaviour of these compounds is scarce, complicating their further study. This review presents current knowledge on immunomodulatory milk protein‐derived peptides, including hydrolysates, peptide fractions and single peptides. The evidence shows that hydrolysates derived from both casein and whey proteins show immunomodulatory effects; however, this bioactivity is mainly attributed to peptides derived from caseins. The identification of peptides in hydrolysates, as well as their characterisation and knowledge of the mechanisms behind their bioactivity, is necessary to further exploit their potential health benefits.     

大豆玉米复合肽液态发酵工艺优化

以豆粕和玉米蛋白粉为原料,应用枯草芽孢杆菌液态发酵制备大豆玉米复合肽。首先考察豆粕和玉米蛋白粉配比、发酵温度、摇床转速、发酵时间和接种量对复配蛋白的水解度和肽转化率的影响。在此基础上应用四因素三水平响应面实验设计对液态发酵工艺进行优化,并建立了相应的回归模型。结果表明,豆粕和玉米蛋白粉配比为2∶1时,液态发酵的优化工艺参数为:发酵温度为37℃、摇床转速为184 r/min、发酵时间为51 h、接种量为4%。在此条件下发酵的蛋白水解度为25.73%±1.78%、肽转化率为33.23%±1.06%,与理论预测值基本相符。该研究结果为豆粕和玉米蛋白粉的深加工及综合利用提供科学参考。      

超声波辅助酶法制备大豆蛋白抗氧化肽的研究

采用超声波辅助木瓜蛋白酶水解大豆蛋白的方法制备抗氧化肽。结果表明,大豆蛋白的最佳水解条件如下:90℃预处理15min,pH6.5,[E]/[S]为7%,超声波处理30min,65℃水解3h,水解度可达19.2%。大豆蛋白肽抗氧化性的高低和水解度的大小没有直接的线性关系,采用此法制备大豆蛋白抗氧化肽的效果较好,具有良好的应用前景。     

Preparation,properties, and uses of enzymatic milk protein hydrolysates

Enzymatic hydrolysis of milk proteins has been a subject of numerous research studies and patents. The driving force for these studies has been the increased utilization of milk proteins. The industrial uses of milk proteins are based on their unique composition, functionality, and nutritive values. The diversity of milk protein fraction, the large number of proteinases, and controlled hydrolysis conditions used resulted in the preparation of hydrolysates suitable for several purposes. Enzymatic hydrolysis of milk proteins modifies the techno-functional and biofunctional properties of hydrolysates depending on the enzyme(s) and hydrolysis conditions used. Milk protein hydrolysates (MPH) are used commonly in normal and clinical nutrition and as a functional food ingredient. In the present review, emphasis has been made to highlight methods applied for the preparation of MPH, and the functional properties and utilization of the obtained hydrolysates.     

大豆蛋白和玉米蛋白酶解肽及其活性研究

将大豆蛋白和玉米蛋白按一定比例复配,采用碱性蛋白酶酶解。当酶解条件为:pH=10,45℃,酶解3h,酶浓度为7u/ml,底物浓度为0.8g/50ml时,复配物的水解度及氮溶解指数均最高,且具有较好的抗油脂氧化能力;酶解物的抗羟基自由基活性与水解度并非正相关关系,水解时间是影响·OH抑制率的主要因素,水解2h时,酶解物对·OH的抑制率高于80%。氨基酸分析表明:两种蛋白质复配后营养价值提高,可作为生产高F值寡肽的原料。     

Assessment of the residual immunoreactivity of soybean whey hydrolysates obtained by combined enzymatic proteolysis and high pressure

Soybean (Glycine max) whey was hydrolyzed for 15 min using three food-grade proteases (Alcalase, Neutrase, Corolase PN-L) at atmospheric pressure (0.1 MPa) and under high pressure (HP) at 100, 200, and 300 MPa. All hydrolysates were analyzed by SDS-PAGE and their residual immunoreactivity was assessed by immunoblotting using the sera from children allergic to soybean. As shown in SDS-PAGE, Alcalase, Neutrase, and Corolase PN-L produced different patterns of hydrolysis. Each enzyme showed a similar proteolytic activity at atmospheric pressure and at 100 MPa, while an increased degree of hydrolysis was observed at 200 and 300 MPa. No residual antigenicity was observed in the hydrolysates obtained by Alcalase and Corolase PN-L in all considered conditions of hydrolysis. A positive reaction associated with a band having molecular weight of about 70 kDa was observed in the immunoblotting of the hydrolysates obtained with Neutrase at 0.1, 100, and 200 MPa, while no antigenicity was detected for those samples obtained under high pressure, at 300 MPa. These results suggest that high pressure combined with suitable enzymatic activity could be a useful tool for obtaining hydrolysates with low immunoreactivity to be used in special foods (hypoallergenic foods).     

木瓜蛋白酶水解绿豆蛋白制备可溶性肽的研究

通过研究木瓜蛋白酶对绿豆蛋白的水解作用,分析了酶浓度、底物浓度、温度、pH、水解时间等因素对水解度的影响,从而确定木瓜蛋白酶水解绿豆蛋白制备绿豆多肽的最佳水解条件,并利用葡聚糖凝胶（SephadexG-15）柱层析测定绿豆多肽分子量。实验结果表明,当水解度为30%时,绿豆多肽分子量绝大多数在1000Da以下。      

鹰嘴豆肽、大豆肽功能性质的研究

研究对比了鹰嘴豆肽和大豆肽的水解度、抗氧化性、吸油性、吸湿及保湿性等功能特性的差异,以及蛋白酶种类对肽产物功能性质的影响。结果表明,①酶Ⅱ(Protease from Bacillus sp.)制备的蛋白肽抗氧化性和吸油能力最好,且在低湿度下的吸湿性和高湿度下的保湿性也最好;酶Ⅲ(Papain from papaya latex)制备的蛋白肽水解度最高;酶Ⅰ(Protease fromAspergillus melleus)制备的蛋白肽在不同湿度条件下都有较好的吸湿性能。②大豆肽的水解度和抗氧化能力比鹰嘴豆肽好。③Desi肽吸油能力最强,在抗氧化性上仅次于大豆肽,高低湿度环境下都有很好的保湿能力,其中Desi肽Ⅱ这些特征最为明显。④Kabuli肽在不同湿度条件下的吸湿和保湿能力都较好。     

Purification and identification of immunomodulating peptides from enzymatic hydrolysates of Alaska pollock frame

To prepare immunomodulating peptides from Alaska pollock frame (APF) hydrolysates, trypsin was employed for enzymatic hydrolysis, and the immunomodulating activities of the hydrolysates were studied using splenic lymphocytes proliferation assay. The highest activity of the hydrolysates was reached when DH ranged from 15% to 18%. The peptide fractions which exhibited the highest activity were further purified using ion exchange chromatography, gel filtration chromatography, and RP-HPLC. The peptides were identified using nano-LC-ESI mass spectrometry. Finally, three immunomodulating peptides were obtained, and the amino acid sequences were Asn-Gly-Met-Thr-Tyr, Asn-Gly-Leu-Ala-Pro, and Trp-Thr, respectively. The lymphocyte proliferation rates were 35.92%, 32.96%, and 31.35% in the presence of 20 μg/ml purified peptides, respectively. Therefore, the results demonstrated that the APF proteins hydrolysates prepared by trypsin could serve as a source of peptides with immunomodulating activity. It provided a scientific basis for the preparation of immunomodulating peptides.     

大豆蛋白活性肽的研究现状及应用前景

介绍了大豆蛋白活性肽的理化特性、生物活性,大豆蛋白活性肽的研究进展及目前所存在的问题.由于大豆肽具有各种生理功能和良好的理化性能,决定了大豆肽除了有很高的生理活性和营养价值外,还具有很好的加工性能.大豆蛋白活性肽的应用将具有广阔的发展前景.     

Purification and identification of angiotensin converting enzyme inhibitory peptides from beef hydrolysates

Sarcoplasmic protein extracts from beef rump (biceps femoris) were hydrolyzed (for 0, 4, 8, 12, and 24 h) with three enzymes or their paired combinations. Ultrafiltration, gel-filtration, and RP-HPLC were used to separate angiotensin converting enzyme (ACE) inhibitory peptides from the hydrolysates. The highest ACE inhibitory activity of enzyme hydrolysates resulted from 4 h incubation with enzymes or their paired combinations. The activities of gel filtrated fractions from these hydrolysates were assayed in vitro, demonstrating that the 3rd peak of enzyme thermolysin + proteinase A hydrolysate had the highest ACE inhibition activity (52.8%). The 3rd peak of this hydrolysate was separated by RP-HPLC into five peaks, of which peak 3 showed 30.1% ACE inhibition activity. Its peptide sequence was determined to be Val-Leu-Ala-Gln-Tyr-Lys. The results suggested that this peptide may be a potent ACE inhibitor which might perhaps be used to develop beef with a bioactive peptide to lower blood pressure.     

大豆肽营养功能及脱苦方法研究进展

大豆肽系由大豆蛋白经水解所得,由3～6个氨基酸残基组成,分子量以低于1000Da为主低分子肽混合物;大豆肽生产和应用前景广阔,市场潜力巨大。该文论述大豆肽营养功能特性及脱苦方法研究进展,并对其发展趋势进行分析。     

Purification and characterization of antioxidative peptides derived from rice bran protein hydrolysates

Rice bran protein fraction (RBPF)—albumin, globulin, glutelin and prolamin were hydrolyzed with proteases M, N, P, S and pepsin under their optimal conditions for 24 h. Hydrolysates of various hydrolysis periods were collected and subjected to peptide mapping and the antioxidative activity measured by the 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic Acid (ABTS) method. Protease M hydrolysates showed high degree of hydrolysis (DH), but low antioxidative activity. On the contrary, pepsin hydrolysates showed low DH with high activity. Albumin and globulin hydrolysates had higher DH values, but lower values for glutelin and prolamin. The globulin hydrolysate (Opep2) from 2 h-pepsin hydrolysis was separated by using three consecutive purification steps with RP-HPLC. Nineteen antioxidative peptides were isolated and their amino acid sequences were determined by a gas-phase protein sequencer and MALDI-TOF mass spectrometry. These peptides were composed of 6–30 amino acid residues with molecular masses ranging from 670–3,611 Da. Tyr-Leu-Ala-Gly-Met-Asn had the highest antioxidative activity among them.     

乳源蛋白中的活性肽及其生理作用

乳源蛋白了营养作用外,还具有生物活性作用,这是由于其中存在着生物活性肽的缘故。这些活性作用包括：阿片活性、等作用。叙述了乳源蛋白中的活性肽及其生理作用。     

大豆多肽特性及其应用研究现状

本文主要综述了大豆多肽加工工艺流程、大豆多肽加工特性和功能特性及当前研究现状,并对今后发展提出几点展望。     

液态发酵大豆肽分子量分布与酶分布关系研究

大豆肽在食品和保健品领域应用广泛,是一种颇有前途功能性食品,大豆粕含45.0%～55.0%大豆蛋白,经水解可得由3～6个氨基酸组成功能性大豆肽。发酵过程中,低分子量肽百分含量、肽转化率和酶分布与发酵条件有关,利用枯草芽孢杆菌1389、黑曲霉3.350和米曲霉A–9005发酵大豆粕,通过这些微生物所分泌各种蛋白酶对大豆粕蛋白质合适位点切割,及对某些肽基团和疏水性氨基酸末端进行修饰和重排,可达到降低成本、提高利用率和产率目的。该实验研究枯草芽孢杆菌1389分别和黑曲霉3.350、米曲霉A–9005混合发酵大豆粕制备大豆肽动态发酵过程中低分子量肽百分含量、肽转化率和酶分布之间相关性;结果表明,发酵温度30℃,接种量为10%,底物浓度3%,枯草芽孢杆菌1389与黑曲霉3.350菌种混合比3∶2,发酵36h时,低分子量肽百分含量65%以上,肽转化率70%左右,为最佳发酵条件。     

菜籽源锌螯合肽的制备、纯化和结构解析

采用碱性蛋白酶水解菜籽蛋白制备水解物,运用固定金属亲和层析(IMAC-Zn2+)和葡聚糖凝胶G25(Sephadex G25)层析分离纯化;利用反相高效液相色谱(RP-HPLC)和电喷雾电离质谱(ESI-MS)鉴定序列;采用EDTA络合滴定法(ECT)、双硫腙比色法(DCM)、原子吸收光谱(AAS)和电感耦合等离子体原子发射光谱法(ICP-AES)检测锌螯合率。试验表明:菜籽蛋白的4 h水解物锌螯合潜力最佳;分离该水解物获得3个肽组分(I,Ⅱ和Ⅲ),其中Ⅱ和Ⅲ具有锌螯合能力;进一步分离后分别获得3个(Ⅱ-1,Ⅱ-2,Ⅱ-3)和2个肽组分(Ⅲ-1和Ⅲ-2),组分Ⅱ-3的锌螯合率最高,高于同浓度的谷胱甘肽(GSH)(P0.05);鉴定Ⅱ-3序列获得4条肽,即Ala-Arg(AR),Asn-Ser-Met(NSM),Gly-Lys-Arg(GKR)和Glu-Pro-SerHis(EPSH)。其中NSM的锌螯合率最高,来源于菜籽蛋白NADH-enoyl-ACP reductase Chain A序列中的296-298氨基酸残基。因此,菜籽蛋白可以作为微量元素螯合肽的优良来源。