共查询到18条相似文献，搜索用时 578 毫秒
1.
以牦牛乳酪蛋白为原料,利用碱性蛋白酶、木瓜蛋白酶和胰蛋白酶制备酪蛋白酶解产物,研究其二肽基肽酶-Ⅳ(dipeptidyl peptidase-Ⅳ,DPP-Ⅳ)抑制活性和理化特性.以DPP-Ⅳ抑制率为指标,研究水解时间和蛋白酶的种类对酶解产物DPP-Ⅳ抑制活性的影响,以水解度、三氯乙酸氮溶解指数(trichloroacetic acid-nitrogen soluble index,TCA-NSI)、溶解性和灰分含量为指标,评价酶解产物的理化特性.结果表明:对于相同水解时间点获得的酶解产物,木瓜蛋白酶酶解产物的DPP-Ⅳ抑制活性显著高于其他2种蛋白酶的酶解产物(P＜0.05).利用木瓜蛋白酶水解0.50 h的酶解产物具有最高的DPP-Ⅳ抑制活性(抑制率可达(53.95±1.57)％)、较高的水解程度以及最低的灰分含量.说明利用蛋白酶水解技术能够使牦牛乳酪蛋白中具有DPP-Ⅳ抑制活性的多肽释放,木瓜蛋白酶酶解产物可作为功能性乳基料用于功能性食品的开发. 相似文献
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《黑龙江畜牧兽医》2014,(15)
为了探明蛋白酶水解作用对牛乳酪蛋白(CN)致敏性或者抗原性的影响,试验采用小鼠动物模型从体外和体内2个方面研究了水解作用对牛乳酪蛋白抗原性的影响。结果表明:胰蛋白酶水解的最适条件为50℃,E/S为0.5%下水解2 h;此水解条件下酪蛋白的总致敏性降低最多,α-酪蛋白(α-CN)抗原性降低率为81.59%,β-酪蛋白(β-CN)抗原性降低率为62.69%。酶解组小鼠过敏症状比未水解的牛乳酪蛋白组相比明显减轻;与未水解酪蛋白相比,酶解物显著抑制特异性免疫球蛋白E(IgE)的产生;酶解物显著降低血浆中组胺的释放。说明胰蛋白酶能够有效降低牛乳酪蛋白的抗原性。 相似文献
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为了筛选生产大豆虾粉肽的适宜蛋白酶及酶解条件,试验采用单因素试验设计,以水解度为检测指标,按酶浓度、底物浓度、pH值、酶解温度和酶解时间逐一分别对3种微生物发酵产生的酸性蛋白酶、碱性蛋白酶和中性蛋白酶水解脱皮豆粕和虾粉混合蛋白的适宜酶解条件进行筛选.试验结果表明:酶解体系中的酶浓度、底物浓度、pH值、酶解温度和酶解时间均显著影响3种蛋白酶对脱皮豆粕和虾粉混合蛋白的酶解效果.在3种蛋白酶中,酸性蛋白酶的酶解效果最好,其次是碱性蛋白酶,中性蛋白酶的酶解效果最差.酸性蛋白酶水解脱皮豆粕和虾粉混合蛋白的适宜条件为:酶浓度为2000 U/g,底物浓度为9%,pH值3.5,酶解时间为3.5 h,温度50℃. 相似文献
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以猪小肠黏膜提取肝素后的滤渣为原料,利用木瓜蛋白酶和中性蛋白酶对猪肠膜进行双酶分阶段水解。在单因素试验的基础上采用正交试验对水解条件进行优化。结果表明:木瓜蛋白酶和中性蛋白酶双酶分阶段水解的最佳酶解工艺为:木瓜蛋白酶-中性酶的加酶量比为1:2,总酶量8000U/g蛋白,底物浓度为5%,pH7.0,温度55℃,酶解时间3h。通过喷雾干燥生产出成品,其蛋白质含量为37.5%。 相似文献
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《蚕业科学》2015,(4)
建立并优化以雄蚕蛾蛋白粉为原料酶解制备活性肽的工艺技术,有助于研发具有功能活性的雄蚕蛾保健产品。首先以雄蚕蛾蛋白的水解度和肽得率为考核目标,对酶解工艺中的酶解液p H、反应温度、反应时间、酶种类及其配比、料液质量浓度及酶用量等因素进行单因素试验。然后采用Box-Benhnken中心组合试验设计法对酶解条件进行优化,建立p H、温度、时间、料液质量浓度等4个因素的酶解效率预测回归模型,并使用Design-Expert 8.0软件对数据做回归分析,验证试验结果提示建立的雄蚕蛾蛋白酶解效率预测回归模型对实测数据有较好的拟合性。最终确定以Alcalase蛋白酶和丹尼斯克碱性蛋白酶对雄蚕蛾蛋白粉进行联合酶解的最佳工艺条件为:酶解液p H 9.5,反应温度55℃,反应时间130 min,料液质量浓度70 g/L。在此优化工艺条件下,雄蚕蛾蛋白粉的水解度为27.32%,肽得率为50.43%,酶解效率综合值为40.47%。 相似文献
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酶解蚕蛹蛋白制备血管紧张素转换酶抑制肽的工艺优化 总被引：2，自引：0，他引：2
采用碱性蛋白酶水解蚕蛹蛋白,制备血管紧张素转换酶(angiotensin-converting enzyme,ACE)抑制肽,是蚕蛹蛋白深度开发的途径之一。以ACE抑制率为响应值,用响应面分析法研究酶解温度、酶解pH和加酶量等因素对酶解产物的ACE抑制活性的影响,优化制备工艺。结果表明,各因素对制备ACE抑制肽的活性影响程度由大到小依次为酶解pH、酶解温度、加酶量。获得碱性蛋白酶水解蚕蛹蛋白制备ACE抑制肽的最佳工艺条件为:酶解温度50.8℃,酶解pH 9.0,加酶量3 500 U/g。在此条件下,蚕蛹蛋白酶解产物对ACE的理论抑制率最高可达96.67%,验证值为96.49%±1.75%,IC50值为0.102 mg/mL,预测模型可靠性高,可应用于蚕蛹ACE抑制肽的酶法制备。 相似文献
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以酪蛋白为研究对象，选取复合风味蛋白酶、胰蛋白酶、胰凝乳蛋白酶、碱性蛋白酶、木瓜蛋白酶、菠萝
蛋白酶和中性蛋白酶共7 种食品级蛋白酶，对牛乳酪蛋白进行酶解。通过牛乳过敏患者血清池，评估酶解产物致敏
原性，同时结合水解产物的分子质量分布、水解度、残留表位信息等指标，筛选出最适合用于生产低致敏酪蛋白产
品的蛋白酶。结果表明：在相同条件下经胰凝乳蛋白酶、复合风味蛋白酶处理后酪蛋白与特异性抗体结合能力降低
程度最大，可用于后续低致敏酪蛋白制备的候选蛋白酶；结合T细胞表位预测结果，对酪蛋白水解产物进一步分析
发现，酪蛋白经过胰凝乳蛋白酶酶解后，仅剩余1 条大于9 个氨基酸的T细胞表位肽段LHSMKEGIHAQQK。 相似文献
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母乳是婴幼儿的最佳食物来源,而乳清蛋白是营养和活性物质的基础,其中生物活性肽对人体健康具有重要促进作用.为研究母乳乳清蛋白抗氧化活性肽,采用中性蛋白酶、碱性蛋白酶、木瓜蛋白酶和胰蛋白酶4种酶制备抗氧化活性多肽,通过单因素试验和响应面分析对乳清蛋白酶解工艺进行优化.结果表明:中性蛋白酶最适于母乳乳清蛋白抗氧化肽的制备,此时的最佳工艺参数为pH 7.21、反应温度50.03℃、酶与底物比(E/S)4 486.68 U/g、酶解时间5h;影响1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率的因素大小为:酶与底物比＞温度＞pH值.利用大孔树脂、葡聚糖凝胶过滤色谱G-25、G-15分析得出组分峰Ⅰ抗氧化活性最强,其DPPH自由基清除率达到了60.31％. 相似文献
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The development of angiotensin I-converting enzyme inhibitor derived from chicken bone protein 总被引：1，自引：1，他引：0
Fu-Yuan CHENG Yu-Tse LIU Tien-Chun WAN Liang-Chuan LIN Ryoichi SAKATA 《Animal Science Journal》2008,79(1):122-128
In order to produce angiotensin I‐converting enzyme (ACE) inhibitor for application in functional food, chicken bones were gathered from a meat processing factory and then hydrolyzed with Alcalase, pepsin and trypsin for 12 h. The hydrolysates were lyophilized, stored at ?80°C and tested experimentally every 2 h for pH value, peptide content, degree of hydrolysis (DH), electrophoresis and activity of ACE inhibitor. The hydrolysates of Alcalase had the highest peptide content and DH. The components of more than 66 kDa had disappeared in hydrolysates of Alcalase and trypsin after 2 h of hydrolysis. The hydrolysates of Alcalase were more active in inhibiting ACE, especially when hydrolyzed at 4 and 8 h, and also had low IC50 values of 1.960 and 0.945 mg/mL. According to the results of DH and electrophoresis, the higher activity of ACE inhibitor is assumed to be derived from the low molecular peptides in hydrolysates of Alcalase. Chicken leg bone has a high potential to be utilized to develop ACE inhibitory peptides as a potential ingredient of functional food intended to alleviate hypertension. 相似文献
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对新疆双峰驼乳酪蛋白分别进行胃蛋白酶和胰蛋白酶的单酶和双酶联合水解,用反相高效液相色谱外标法,对产生的马尿酸含量进行检测,测定水解产物血管紧张素转化酶（angiotensin converting enzyme,ACE）抑制活性。通过米式方程对比水解产物与卡托普利之间的竞争关系,并用50、10、3 kDa的超滤膜对水解液进行超滤,测定截留液ACE抑制活性。结果表明：驼乳酪蛋白单酶水解12 h过程中,胰蛋白酶水解4 h,水解度达到3.7%,胃蛋白酶水解4 h,水解度达到16.58%,胰蛋白酶水解2 h,水解 相似文献
14.
JIANG Jing Ao-ri-ge-le WANG Chun-jie ZHANG Yan ZHAO Chen-he WU Hong-jun HAO Jian-gang 《中国畜牧兽医》2016,43(2):444-449
To study the physicochemical properties extracted from koumiss of Lactobacillus plantarum DSM20174 bacteriocin,we purified the Lactobacillus plantarum DSM20174 bacteriocins and got the bacteriocin crude extractions after ammonium sulfate precipitation and dialysis.After purification with Sephadex G-100 gel column chromatography,bacteriocin specific activity apparently increased,reaching 154.70 AU/mL,yield was 43.5%.We detected the effects of purified Lactobacillus plantarum DSM20174 bacteriocin on bacteriostatic action of wild bovine pathogenic E.coli O78 by Oxford cup method under 3 different treatments.The results showed that:①In five groups of temperature treatments,the bacteriostatic action decreased with the increase of temperature,bacteriostatic actions of all groups were significantly different (P<0.05).Even after treatment at 121 ℃ 30 min,antimicrobial diameter was 14.90 mm.② After Lactobacillus plantarum DSM20174 bacteriocin were treated with pH 2.0 to pH 12.0,the higher of pH,the smaller of antibacterial diameter.The inhibitory effect of groups were significantly different (P<0.05) except pH 9.0 and pH 10.0.③Lactobacillus plantarum DSM20174 bacteriocins were treated by trypsin,pepsin and papain,antibacterial diameter apparently changed,bacteriostatic action was significantly different (P<0.05) before and after treatment.The results suggested that Lactobacillus plantarum DSM20174 bacteriocins were better antibacterial substances,but not thermal stability substances.It had a relatively wide pH range,and the smaller of pH,the stronger of its antibacterial activity,the antibacterial activity had been enhanced at optimum growth pH.It was not protease stability substances. 相似文献
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为研究从酸马奶中提取的植物乳杆菌DSM20174细菌素的理化特性,本试验提纯植物乳杆菌DSM20174细菌素,经过硫酸铵沉淀、透析后得到细菌素粗提液,再利用SephadexG-100凝胶柱层析进行纯化后,细菌素的比活力明显增加,达到154.70 AU/mL,得率为43.5%.采用牛津杯法测定纯化的植物乳杆菌DSM20174细菌素在3种不同方式处理下对牛源野生致病性大肠杆菌O78抑菌效果的影响.结果显示:①植物乳杆菌DSM20174细菌素在5组温度处理下,随着温度的升高抑菌作用降低,各组抑菌作用差异显著(P<0.05).即使121 ℃处理30 min后,抑菌直径仍达14.90 mm.②植物乳杆菌DSM20174细菌素在pH 2.0~12.0由低到高的11组酸碱处理下,pH越大抑菌直径越小,且除了pH 9.0和pH 10.0之间差异不显著(P>0.05)外,其余各组抑菌作用均差异显著(P<0.05). ③植物乳杆菌DSM20174细菌素经胰蛋白酶、胃蛋白酶、木瓜蛋白酶3种酶处理后抑菌直径变化明显,处理前后抑菌作用均差异显著(P<0.05).结果表明植物乳杆菌DSM20174细菌素是较好的抑菌活性物质,但不是热稳定性物质;具有较广泛的pH适用范围,且pH越小时其抑菌活性越强,在最适生长pH时抑菌活性有所增强;不是蛋白酶稳定性物质. 相似文献
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以绵羊乳酪蛋白为原料,采用中性蛋白酶水解制备生物活性肽,研究酶解时间对酶解产物水解度和血管紧张素转换酶（angiotensin converting enzyme,ACE）抑制率的影响,利用液相色谱-质谱联用技术对水解产物进行分析和鉴定,筛选具有潜在ACE抑制作用的生物活性肽。结果表明：酶解时间达到300 min时,水解度最高值达9.65%,ACE抑制率为84.55%;当ACE抑制率达到50%时,所需肽段YYQQRP浓度为5～10 μmol/L;利用超高效液相色谱飞行时间质谱仪对酶解后的多肽进行序列分析, 相似文献
17.
MAO Xin ZHANG Guizhen QU Jinyao ZHANG Yuhao LU Guozhu GAO Yonglin LI Yanshen 《中国畜牧兽医》2007,47(12):4093-4102
The aim of this study was to search for novel non-ribosomal peptide antimicrobial substances based on the screening of bacterial secondary metabolites.The bacteria isolated from soil,sea water and common marine organisms in Yantai coastal area were isolated and purified.E.coli ATCC 25922 and Staphylococcus aureus ATCC 29213 were selected as indicator bacteria,and E.coli B2 (blaNDM-5+mcr-1) and methicillin-resistant Staphylococcus aureus (MRSA) T144 were used as indicator for secondary screening.The genome was extracted and the PCR products were sequenced to determine the active species.The secondary metabolites of bacteria were extracted by organic extraction,purified by gel chromatography and preparative liquid chromatography,and purity was detected by analytical liquid chromatography.The results of sequencing showed that the active strain belonged to Bacillus amyloliquefaciens sp.,and was named as Bacillus amyloliquefaciens 9-14 (active bacterium 9-14).The results of antibacterial test showed that the metabolites of active bacterium 9-14 had high inhibitory effect on Staphylococcus aureus ATCC 29213,MRSA T144,E.coli ATCC 25922 and E.coli B2.The metabolites of active bacterium 9-14 were cyclic lipopeptides composed of amino acid chains,which belonged to the derivatives of ibuprofen.The biological characteristics and antibacterial spectrum of the metabolites of active bacterium 9-14 were studied.The results showed that the metabolites of active bacterium 9-14 had good thermal stability and acid-base stability.And the antibacterial activity of the antibacterial substance treated with trypsin,pepsin,protease K and papain was not significantly weakened and had good stability.The antibacterial substance also had inhibitory effect on Staphylococcus aureus and E.coli,but had no activity against Pseudomonas aeruginosa,Klebsiella pneumoniae,Enterococcus faecalis and Bacillus cereus.In this study,a new antibacterial substance was obtained,which could be used as the precursor of antibacterial drugs,and could provide certain reference for food safety and disease control. 相似文献
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本研究旨在基于对细菌次级代谢产物的筛选,寻找新型非核糖体肽类抗菌物质。通过对烟台沿海地区的土壤、海水及近海常见海洋生物中的细菌进行培养,分离纯化得到细菌的单克隆,以大肠杆菌（E.coli）ATCC 25922和金黄色葡萄球菌ATCC 29213为指示菌进行初步筛选,以耐多黏菌素和碳青霉烯E.coli B2（blaNDM-5+mcr-1）和耐甲氧西林金黄色葡萄球菌（MRSA） T144作为指示菌对有活性的细菌进行二次筛选。通过提取基因组进行PCR扩增产物测序比对,确定活性菌种属。采用有机萃取法对细菌的次级代谢产物进行萃取,通过凝胶层析和制备液相色谱进行纯化,利用分析型液相色谱进行纯度检测,进—步利用质谱对纯化后的抗菌活性物质进行结构鉴定。测序结果表明,活性菌属于解淀粉酶芽孢杆菌种,将其命名为解淀粉酶芽孢杆菌9-14（活性菌9-14）。抑菌试验结果表明,活性菌9-14的代谢产物对金黄色葡萄球菌ATCC 29213、MRSA T144、E.coli ATCC 25922和E.coli B2均具有高效抑制作用。活性菌9-14代谢产物是由氨基酸链组成的环状脂肽,属于伊枯草菌素的衍生物。对活性菌9-14代谢产物的生物学特性及其抑菌谱研究发现,活性菌9-14的代谢产物具有良好的热稳定性和酸碱稳定性,该抗菌物质经胰蛋白酶、胃蛋白酶、蛋白酶K和木瓜蛋白酶处理后抗菌活性没有明显减弱,具有较好的稳定性;该抗菌物质对所用金黄色葡萄球菌和大肠杆菌同样具有抑制作用,对绿脓杆菌、肺炎克雷伯杆菌、粪肠球菌和蜡样芽孢杆菌均不表现活性。本研究得到一种新型的抗菌物质,以该抗菌物质为抗菌药物的前体,可为食品安全和疾病控制提供一定的参考依据。 相似文献