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以谷朊粉为原料,以血管紧张素转换酶(ACE)抑制率为指标,比较4种蛋白酶的酶解效果。采用超滤、葡聚糖凝胶色谱、反相高效液相色谱(RP-HPLC)的方法分离纯化ACE抑制肽并用电喷雾飞行时间质谱联用(ESI-TOF-MS)鉴定其结构。结果表明:碱性蛋白酶酶解3 h的谷朊粉酶解物具有较高的ACE抑制活性;超滤后,分子质量Mr<1 ku的组分具有较高的ACE抑制率;分离纯化后得到小肽的ACE抑制率高达(81.03±1.20)%;由ESI-TOF-MS质谱图得出该小肽的m/z为630.89,氨基酸序列为Trp-Phe-Gln-Pro(WFQP)。 相似文献
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小麦谷朊蛋白ACE抑制肽分离纯化研究 总被引:1,自引:0,他引:1
为了探讨和研究小麦谷朊蛋白ACE抑制肽分离提纯方法、技术参数及分离效果,首先采用超滤、纳滤膜技术将谷朊蛋白水解液按照相对分子质量的不同进行分离纯化,采用高效液相色谱法和SHR大鼠实验检ACE抑制抑制效果,并对高抑制活性的组分采用凝胶排阻色谱(Sephadex G-25)进一步分离纯化。结果显示膜过滤和凝胶排阻色谱(Sephadex G-25)能够有效分离和纯化谷朊蛋白抑制肽,IC50由0.125mg/mL降低到0.106mg/mL。一次性灌胃SHR大鼠一星期后动脉血压降低(8.86±2.23)mmHg,证明谷朊蛋白抑制肽经过分离纯化后具有良好的降血压效果。 相似文献
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响应面法对酶水解谷朊粉制备生物活性肽的优化研究 总被引:9,自引:0,他引:9
以谷朊粉为原料,用复合蛋白酶水解,制备生物活性肽,并对其水解工艺进行优化。在单因素实验中,研究了时间、温度、pH值、谷朊粉质量分数和酶浓度5种因素对水解度的影响。在此基础上以水解度、肽含量和还原力为响应值设计了4因素(酶浓度、时间、温度和pH值)3水平的响应面实验。通过响应面实验得到最佳水解条件:时间3h、pH7.3、温度54℃、酶浓度[E/S]是35mg/g和谷朊粉质量分数3%。此时水解度为7.5%,还原力达到最大值0.573,肽含量为0.148mg/ml。结果表明,谷朊粉的水解物——小麦肽具有抗氧化能力。 相似文献
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以小麦淀粉生产的副产物谷朊粉为原料,通过单因素实验和正交实验研究酶解时间、底物浓度、酶浓度、溶液pH、酶解温度对谷朊粉水解度的影响,探索碱性蛋白酶酶解小麦谷朊粉的最佳工艺条件。分析发现五个因素对谷朊粉水解度的影响由强到弱的次序依次为:溶液pH>酶解温度>酶浓度>底物浓度>酶解时间;结果表明:酶解时间3h、底物浓度9%、酶浓度4%、底物pH=8.0、55℃时谷朊粉的水解度最高,此时谷朊粉的水解度为22.96%。在最佳水解条件下通过Tricine SDS-PAGE确定谷朊粉蛋白多肽的分子量分布范围在8.0450.12ku之间。 相似文献
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本文通过比较酶种类、加酶量、底物浓度、酶解温度、酶解时间对短肽得率和水解度的影响,采用二次回归正交旋转组合设计优化分步酶解制备谷朊粉短肽的最佳工艺。在复合蛋白酶(Protamex)水解谷朊粉91.50 min后加入中性蛋白酶(Neutrase)继续酶解121.50 min,Protamex添加量为665.00 U/g底物,Neutrase添加量为5 290.00 U/g底物,水解温度50℃,质量浓度12%,在此条件下,短肽得率为69.88%,水解度25.74%。经高效液相色谱测定,分子质量小于1 000 Da的水解产物占100%。采用Protamex与Neutrase分步酶解谷朊粉制备谷朊粉短肽,与现有制备谷朊粉短肽方法相比,避免了后续脱盐步骤,简化工艺,且具有制备条件温和,TCA-NSI和DH高,纯度高,分子量集中分布于1 000 Da以下等特点。 相似文献
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酶解牛乳酪蛋白制备ACE抑制肽的研究 总被引:2,自引:0,他引:2
目的利用酶技术制备酪蛋白源ACE抑制肽.方法以ACE抑制活性为指标,筛选最佳用酶,优化酶解反应条件,并研究酶解过程中水解度和游离氨基酸含量的变化.结果通过对5种蛋白酶的筛选,最终确定AS1.398中性蛋白酶为水解用酶,制备酪蛋白源ACE抑制肽,其最佳反应条件为pH 7、温度45℃、底物质量分数7.5%、酶用量([E]/[S])5%,水解6 h.在酶解过程中,随着时间的延长,水解度略有增加,而游离氨基酸含量大幅度增加.酪蛋白ACE抑制肽的半抑制浓度(IC50值)为0.68mg/mL.结论牛乳酪蛋白用蛋白酶水解可制备高活性的ACE抑制肽,是获得ACE抑制肽的良好来源. 相似文献
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目的 优化谷朊粉钙离子螯合肽制备工艺并对其结构进行表征。方法 以水解度为指标,探究温度、时间、pH及加酶量等因素对谷朊粉酶解的影响;以钙离子螯合肽生成量为指标,探究不同因素对钙离子螯合肽生产量的影响;并根据结果进行Box-Behnken响应面实验优化螯合工艺。通过扫描电镜分析和红外分析对谷朊粉钙离子螯合肽进行表征。结果 最佳酶解工艺为:液料比17.5:1(mL/g)、碱性蛋白酶和风味蛋白酶添加比例为3:1、加酶量5000 U/g、酶解pH 9、酶解温度50℃、酶解时间4.0 h;优化后的最佳螯合工艺为:螯合温度38℃、肽液浓度13.5%、肽钙比5:1、螯合时间12.0 min、螯合pH 7、静置时间35 min、无水乙醇添加量为7倍体积,在此条件下钙离子螯合肽得率为50.85%。扫描电镜结果显示,螯合肽外观发生明显改变,更有利于吸收;红外光谱分析表明,钙离子可能与谷朊粉多肽上的-NH、-COOH结合。结论 本研究建立的谷朊粉酶解工艺、钙离子螯合工艺可行,可为谷朊粉深加工和产品研发提供思路与理论参考。 相似文献
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小麦面筋蛋白结构、功能性及应用 总被引:7,自引:0,他引:7
小麦面筋蛋白的结构和组成是影响小麦粉面团粘弹性及烘焙品质的重要因素,而且在食品和非食品领域有着广泛的应用。对小麦面筋蛋白的结构、组成对功能特性的影响进行了综述,并简要介绍了小麦面筋蛋白在食品方面的应用。 相似文献
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From 2% (w/w) whey powder in growth media, inhibitory peptides against angiotensin I-converting enzyme (ACE) were studied with nine Lactobacillus species. Lb. brevis, Lb. helveticus and Lb. paracasei were proved to be the most effective strains in liberating ACE inhibitory peptides from whey protein. The inhibition rates of these peptides against ACE ranging from 93.3 to 100%. Several distinct peaks were eluted when the whey proteins were fractionated on a Delta Pak C18 column by reversed phase-high performance liquid chromatography (RP-HPLC). Among ACE inhibitory activities of 14 peptides purified by dialysis and by fractionation using RP-HPLC, two peptide fractions (H5 and H7) of Lb. helveticus showing IC50 values of 5.3 and 7.8 were the most potent ACE inhibitors.
All of these peptides including some other peptides (H1 and B1), having strong inhibitory activities against ACE were pentapeptides positioning with Ala at their N-terminal and these petapeptides had mostly hydrophobic (Pro, Val and Leu) or aromatic (Phe) amino acids at the C-terminal.
There is a significant amount of research and interest in developing and charactering the peptides that inhibit angiotensin I-converting enzyme (ACE) activity as these natural products may have a role in blood pressure control in man. This study revealed that the identification of peptides, mostly composed of pentapeptides following fermentation of whey protein in growth medium with different strains have the ACE inhibitory activities. These peptides may have antihypertensive effect as natural and safe nutraceutical/functional ingredients, though the exact potency of the pentapeptides isolated in this experiment has not been determined. 相似文献
All of these peptides including some other peptides (H1 and B1), having strong inhibitory activities against ACE were pentapeptides positioning with Ala at their N-terminal and these petapeptides had mostly hydrophobic (Pro, Val and Leu) or aromatic (Phe) amino acids at the C-terminal.
PRACTICAL APPLICATIONS
There is a significant amount of research and interest in developing and charactering the peptides that inhibit angiotensin I-converting enzyme (ACE) activity as these natural products may have a role in blood pressure control in man. This study revealed that the identification of peptides, mostly composed of pentapeptides following fermentation of whey protein in growth medium with different strains have the ACE inhibitory activities. These peptides may have antihypertensive effect as natural and safe nutraceutical/functional ingredients, though the exact potency of the pentapeptides isolated in this experiment has not been determined. 相似文献
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IDENTIFICATION OF ANGIOTENSIN I-CONVERTING ENZYME INHIBITORY PEPTIDES DERIVED FROM THE PEPTIC DIGEST OF SOYBEAN PROTEIN 总被引:1,自引:0,他引:1
JIUN-RONG CHEN TAKASHI OKADA KOJI MURAMOTO KUNIO SUETSUNA SUH-CHING YANG 《Journal of Food Biochemistry》2002,26(6):543-554
Peptidic fractions which inhibit angiotensin I‐converting enzyme (ACE) were separated from peptic digests of soybean by ion exchange chromatography and gel filtration. Further separation of the peptidic fractions by ODS HPLC afforded active peptides, the amino add sequences of which were identified by Edman's procedure as: Ile‐Ata (inhibitory against ACE with an IC50of 153 μM), Tyr‐Leu‐Ala‐Gly‐Asn‐Gln (14 μM), Phe‐Phe‐Leu (37 μM), Ile‐Tyr‐Leu‐Leu (42 μM), and Val‐Met‐Asp‐Lys‐Pro‐Gln‐Gly (39 μM). The antihypertensive activity of the soybean peptides was also investigated. Peptide fractions (2.0 g/kg body weight, oral administration) markedly towered the blood pressure of spontaneously hypertensive rats (SHRs). 相似文献
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酶法提取袖珍菇多糖工艺的研究 总被引:2,自引:1,他引:2
用酶解法提取袖珍菇多糖,通过各种酶的比较,选择合适的酶,再研究此酶的酶解时间、酶解浓度、温度、pH等因素对多糖提取率的影响.结果表明,酶解法提取袖珍菇多糖的最佳工艺为:木瓜蛋白酶为2%,温度为50℃,pH为5.2,反应时间为100 min. 相似文献