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1.
杨萍  柯虹乔  章超桦  洪鹏志 《水产学报》2012,36(8):1297-1303
研究大眼金枪鱼头蛋白酶解物1 ku超滤组分体外的还原力、自由基清除能力及对衰老小鼠体内抗氧化能力的影响,分析1 ku超滤组分的一般成分、氨基酸组成及分子量分布,为进一步分离纯化金枪鱼头抗氧化肽提供基础。体外结果显示,1 ku超滤组分对羟基自由基、超氧阴离子和DPPH自由基的清除活性随浓度的增加而增强,IC50分别为1.38、0.73与0.93mg/mL,还原力也随浓度的增加而增大,在浓度为12.5 mg/mL时为0.763;体内结果显示,灌胃30 mg/kg的1 ku超滤组分连续42 d,D-半乳糖致衰老小鼠肝组织的超氧化物歧化酶(SOD)活性、肝组织和血清的谷胱甘肽过氧化物酶(GSH-PX)活性显著提高(P<0.05),血清丙二醛(MDA)含量显著降低(P<0.01);理化分析结果显示,1 ku超滤组分(干基计)蛋白质含量为96.40%,脂肪0.11%,灰分4.86%,疏水性氨基酸占氨基酸总量的35.8%,活性组分分子量在1 802~2 519 u和422~922 u。  相似文献   

2.
杨帆  栗丽  陈荫  王斌  王加斌 《水产学报》2019,43(4):1245-1254
以孔鳐软骨为材料,采用盐酸胍抽提、丙酮分级沉淀,制备孔鳐软骨蛋白;以DPPH·和HO·清除活性为导向,采用胰蛋白酶酶解、膜超滤、DEAE-52阴离子交换层析、Sephadex G-15凝胶层析和反相高效液相色谱(RP-HPLC)等技术,制备抗氧化肽,并对其活性进行系统评价。结果显示,孔鳐软骨蛋白经胰蛋白酶酶解和分离纯化得到2个抗氧化肽RCPE-A和RCPE-B,经氨基酸序列分析确定其序列分别为Gly-Glu-Glu-Gly-Pro-Arg-Gly (GEEGPRG)和Gly-Glu-Glu-Gly-Thr-Met-Gly-Leu (GEEGTMGL),质谱(ESI-MS)测定其分子量分别为700.71和792.87 u。体外自由基清除实验结果显示,RCPE-A与RCPE-B对DPPH·(EC50 2.94和1.16 mg/mL)、HO·(EC50 0.34和0.54 mg/mL)、ABTS+·(EC50 0.34和0.10 mg/mL)和O2-·(EC50 0.11和0.03 mg/mL)具有良好的清除作用,RCPE-A与RCPE-B亦显示出较强的脂质过氧化抑制作用。研究表明,孔鳐软骨蛋白酶解物及制备多肽可用于抗氧化相关的功能食品开发,也可以用作抗氧化剂延长相关产品的货架期。  相似文献   

3.
曾名湧  郭瑶  刘尊英 《水产学报》2008,32(1):117-124
采用菠萝蛋白酶和Alcalase酶依次对尼罗罗非鱼皮胶原进行复合酶解.研究了该酶解产物的体外抗氧化活性.实验表明,该酶解产物具有较强的超氧阴离子/羟基自由基清除活性和还原能力.采用不同截留分子量的超滤膜将该酶解物分离成5个组分,即TGH-Ⅰ(>10 ku),TGH-Ⅱ(10~5 ku),TGH-Ⅲ(5~3 ku),TGH-Ⅳ(3~1 ku)和TGH-Ⅴ(10 ku).其中TGH-Ⅴ组分显示出最强的超氧阴离子自由基清除活性,因此采用凝胶过滤、离子交换和反向高压液相色谱技术对该组分进一步分离纯化.纯化得到的肽具有很强的超氧阴离子自由基清除活性,其IC50值为4.6 μg·mL-1.通过质谱分析可知,该肽的分子量位于311.3~932.8 u之间.  相似文献   

4.
为分析马粪海胆和光棘球海胆性腺的脂质组成和抗氧化活性,采用核磁共振和气相色谱—质谱技术对2种海胆性腺油脂的脂质成分和脂肪酸组成进行分析,并通过DPPH自由基清除法、羟基自由基清除法和超氧阴离子自由基清除法对其脂质的抗氧化活性进行研究。结果显示,马粪海胆和光棘球海胆性腺脂质均以甘油三酯和磷脂为主,胆固醇、胆固醇酯和游离脂肪酸含量较低。马粪海胆和光棘球海胆性腺总脂富含C20:4n-6和C20:5n-3,且二者总量分别占脂肪酸含量的35.88%和34.98%;同时2种海胆性腺的中性脂和极性脂的脂肪酸组成存在较大差异,中性脂以C14:0和C16:0等饱和脂肪酸为主,而极性脂以C20:4n-6和C20:5n-3等多不饱和脂肪酸为主。马粪海胆和光棘球海胆性腺脂质对DPPH自由基、羟基自由基和超氧阴离子自由基均具有较好的清除能力,DPPH自由基IC50分别为2.75和1.98 mg/mL,羟基自由基IC50分别为0.33和0.29 mg/mL,超氧阴离子自由基IC50分别为0.33和0.31 mg/mL。研究表明,马粪海胆和光棘球海胆性腺脂质具有较高的营养价值和抗氧化活性,可作为C20:4n-6、C20:5n-3和磷脂等功能性脂质因子的重要膳食来源。  相似文献   

5.
以印度洋鸢乌贼(Symplectoteuthis oualaniensis)胴体分离蛋白为原料,基于分子量分布和营养价值分析,优化制备抗氧化肽的酶解工艺参数。碱溶酸沉法从鸢乌贼胴体提取分离蛋白;以底物浓度、酶底比、酶解时间等3个因素为单因素实验;Box-Behnken中心法则设计响应面实验;DPPH自由基清除率结合水解度为响应指标。鸢乌贼胴体分离蛋白相对分子量分布在30~240 kDa;必需氨基酸占总氨基酸42.56%;最佳酶解工艺参数是底物浓度4%、酶底比9 U·mg-1、酶解时间4 h。5 mg·mL-1的鸢乌贼胴体分离蛋白酶解物的DPPH自由基清除率为55.60%,羟自由基清除率为53.21%,ABTS自由基清除率为40.12%。鸢乌贼胴体分离蛋白符合FAO/WHO世界卫生组织提出的理想蛋白营养价值模式,鸢乌贼胴体能制备出营养价值高和抗氧化活性强的海洋功能蛋白肽。  相似文献   

6.
龟类不仅营养价值高,而且具有潜在的药用价值,通过研究龟肉酶解产物的功能特性,可以科学认识其营养保健功能.以黄缘盒龟肉为原料,羟自由基清除率为指标,碱性蛋白酶为水解酶,通过正交试验L9(34)得到制备抗氧化肽的最佳酶解条件为pH值8.0、酶解温度55℃、料液比1.5∶20 g/mL、加酶量(酶/底物,E/S)3.0%、酶解时间3h,酶解液对羟自由基清除率达到82.08%.酶解产物体外抗氧化活性的结果表明,酶解产物对羟自由基、超氧阴离子自由基、DPPH自由基和过氧化氢均有较好的清除作用,还具一定的还原能力、亚铁离子螯合能力和亚油酸自氧化抑制能力.总体而言,黄缘盒龟酶解产物在不同的体外抗氧化体系中均表现出一定的抗氧化效果,具有良好的开发利用前景.  相似文献   

7.
本文以红毛藻为研究材料,对红毛藻多糖的提取工艺进行优化,并对其体外抗氧化活性进行研究。实验分别考察红毛藻的提取时间、提取温度、料液比对红毛藻多糖提取量的影响,并结合正交实验设计优选出最佳提取工艺,同时通过体外抗氧化活性评价研究其清除DPPH自由基和羟基自由基的能力。结果表明,以料液比1∶40(m/v)、在90℃下提取2.0 h为最佳提取工艺,在此工艺下红毛藻多糖提取量最高,达到(77.57±2.17)mg/g;体外抗氧化活性评价结果显示,红毛藻多糖对DPPH自由基和羟基自由基具有明显的清除效果,清除DPPH自由基的IC_(50)值为0.36 mg/mL,清除羟基自由基的IC_(50)值为0.65 mg/mL。本研究可为红毛藻多糖的进一步开发应用提供参考。  相似文献   

8.
虾头在一定的条件下发生自溶作用,其所含蛋白质以肽和氨基酸等形式释放出来,有些肽产物具有ACE抑制活性.实验采用8000、5000和3000 u的超滤膜分级分离虾头自溶产物,活性检测结果表明,ACE抑制肽主要分布在3000 u超滤组分中;3000 u超滤组分进一步经Sephadex G-25葡聚糖凝胶层析、SP Sephadex C-25离子交换层析及Sephadex G-15葡聚糖凝胶层析纯化,ACE抑制活性提高将近8倍(IC50 =0.19 mg/mL);Sephadex G-15葡聚糖凝胶层析收集的高活性成分再经两次RP-HPLC纯化,分离纯化得到两条ACE抑制肽,质谱分析推测其氨基酸序列为Tyr-Pro和Leu-Pro/Ile-Pro,分子量分别为279和229 u.  相似文献   

9.
为制备抗氧化活性良好的鲢鱼鱼皮蛋白肽,采用胰蛋白酶、碱性蛋白酶、菠萝蛋白酶和木瓜蛋白酶等4种常见的商业酶对鲢鱼鱼皮进行酶解,测定酶解物的ABTS自由基清除力和Fe2+螯合力来评价其抗氧化活性,并用超滤及凝胶层析对酶解物进行分离,以期得到活性更好的酶解物分离组分。酶解后产物的抗氧化活性均有所提高,其中碱性蛋白酶酶解2 h产物活性较强。对此酶解物用截留分子量为10 k Da、5 k Da和3 k Da的中空纤维超滤膜进行超滤,得到的4个组分中,分子量越小的组分抗氧化活性越强。分子量小于3 k Da的组分经Sephadex G-15凝胶层析得到3个组分,其中分子量最大的组分活性较好,在0.51 mg/m L质量浓度下测定其ABTS自由基清除率和Fe~(2+)螯合力分别为(79.65±0.87)%和(93.40±0.20)%。该研究成果对鲢鱼鱼皮抗氧化肽的开发具有较好的指导作用。  相似文献   

10.
为了探讨不同海藻多糖抗氧化活性的差异,对琼枝(Betaphycus gelatinae)、石莼(Ulva lactuca)、匍枝马尾藻(Sargassum polycystum)、南方团扇藻(Padina australis)和棒叶蕨藻(Caulerpa sertularioides)的粗多糖的自由基清除及脂质过氧化抑制能力进行了研究。结果表明,5种海藻多糖的抗氧化活性存在明显的差异性,南方团扇藻和匍枝马尾藻多糖具有较强的还原力,对超氧阴离子和羟自由基均有较强的清除活性,其中南方团扇藻多糖对超氧阴离子清除活性较强[半抑制浓度(IC_(50))为(262.00±24.60)μg·m L~(-1)],明显高于匍枝马尾藻多糖[IC_(50)=(458.00±18.70)μg·m L~(-1)],对羟自由基的清除活性[IC_(50)=(388.00±45.29)μg·m L~(-1)]与匍枝马尾藻多糖相近[IC_(50)=(312.04±37.42)μg·m L~(-1)],匍枝马尾藻多糖对DPPH的清除能力[IC_(50)=(95.80±7.48)μg·m L~(-1)]显著高于其他4种海藻多糖,而南方团扇藻多糖对DPPH的清除能力较差[IC_(50)=(726.00±54.90)μg·m L~(-1)]。通过体外抗脂质过氧化作用研究发现,南方团扇藻多糖对肝细胞膜脂质氧化有较高的抑制能力[IC_(50)=(283.67±44.14)μg·m L~(-1)],并且对过氧化氢诱导的红细胞溶解有一定的保护能力[IC_(50)=(335.50±22.47)μg·m L~(-1)]。  相似文献   

11.
采用RACE方法,克隆了背角无齿蚌抗菌肽theromacin基因的cDNA全序列。结果显示,该cDNA序列全长为870 bp,5'端非翻译区104 bp,3'端非翻译区460 bp,开放阅读框长为306 bp,共编码101个氨基酸,相对分子量为11 166.9 u。同源性分析显示,该基因编码的蛋白与三角帆蚌theromacin基因氨基酸序列的相似度最高,为73%;与贻贝中发现的抗菌肽defensins、mytilins、myticins和mytimycins等4种类型相似度较低,属于Macin家族(登录号:KJ598604)。实时荧光定量PCR分析结果显示,该基因在血液、肝脏、外套膜、鳃、斧足和肠等组织中均有表达,在外套膜中的表达量最高,在其他组织中的表达量较低;经嗜水气单胞菌诱导后,各个组织的表达量出现明显上调的趋势且与对照组显著差异,推测theromacin基因可能在背角无齿蚌的免疫反应中起重要作用。  相似文献   

12.
采用qRT-PCR、RACE等方法,获得了拟穴青蟹丝裂原活化蛋白激酶激酶(MAPKK)基因cDNA全长序列。该基因全长1 558 bp,开放阅读框长度为1 224 bp,编码407个氨基酸残基。同源分析显示,该基因编码的蛋白与昆虫的相似性高达70%,推测MAPKK基因在节肢动物具有较高的保守性。经荧光定量PCR检测,MAPKK基因在拟穴青蟹多个组织中有表达,且在脑神经节和卵巢中表达量较高。在拟穴青蟹卵巢发育过程中,MAPKK基因在卵巢发育期(Ⅲ期)表达量最高,发育期为卵母细胞快速生长期,推测MAPKK具有促进卵母细胞快速生长的作用。  相似文献   

13.
Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) were isolated from rohu skin with the yield of 64.2 and 6.8% (dry weight basis), respectively. Both collagens had glycine as the major amino acid with imino acid content of 196–202 residues/1,000 residues and were characterized as type I collagen with molecular composition of (α1)2α2-heterotrimer. Fourier transform infrared spectra of both collagens were similar, with no shift in wavenumber of all amide bands. The Tmax value of ASC and PSC was 36.40 and 35.48°C, respectively. The zero surface net charge of ASC and PSC was found at pH 5.9 and 5.3, respectively.  相似文献   

14.
ABSTRACT

The major objective of this study was to investigate the pepsin digests of cutlassfish muscle for their antioxidant activity. The peptide isolated after 3 h of pepsin hydrolysis demonstrated the highest scavenging activity for both 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and alkyl radicals. It also had the highest yield of the isolates with the highest protein content, which was likely related to its higher degree of hydrolysis than the other hydrolysates. The antioxidant peptide purified from the 3 h pepsin hydrolysate indicated the amino acid sequence, Phe-Ser-Gly-Gly-Glu. This study suggests that cutlassfish muscle is an excellent antioxidant source and could be effectively used as a food ingredient and in pharmaceuticals.  相似文献   

15.
Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) from golden pompano skins were extracted and characterized. The molecular weight of ASC was about 130 kDa for α1 and 115 kDa for α2, which were slightly higher than those of PSC. Similar amino acid composition and Fourier transform infrared (FTIR) spectra were observed in both collagens, but slight differences were found in the peptide maps of collagen digested by V8 protease and trypsin. The denaturation temperatures (Tds) of ASC and PSC calculated from the reduced viscosity were 31.8 and 30.0°C, while the transition temperature (Tm) of ASC and PSC analyzed by DSC were 33.0 and 32.0°C, respectively. ASC has a lag phase, a growth phase, and a plateau phase in the turbidity–time curve, while PSC does not have similar phenomenon. It was found that the fibril gel of ASC could be formed at 25°C, leading to improved thermal stability.  相似文献   

16.
The antioxidant activities of enzymatically hydrolyzed (protease from Bacillus cereus SU12) oyster (Saccostrea cucullata) protein were studied. The hydrolysate exhibited a strong antioxidant potential in 1, 1-diphenyl-2-picrylhydrazyl (DPPH, 85.7 ± 0.37%), followed by hydrogen peroxide radical scavenging activity (81.6 ± 0.3%), hydroxyl radical scavenging activity (79.32 ± 0.6%), and reducing power assay (2.63 ± 0.2 OD at 700 nm) at a concentration of 1 mg/mL. Due to the high antioxidant potential, the hydrolysate was purified in Sephadex G-25 gel filtration chromatography. The active peptide fraction was identified by DPPH and reducing power assay. The amino acid content of the purified active peptide fraction was analyzed by high performance liquid chromatography. The active fraction contained a good quantity of both essential and nonessential amino acids. The present study revealed that oyster (S. cucullata) protein hydrolysate is a potential source for natural antioxidants.  相似文献   

17.
李燕  周志刚 《水产学报》2014,38(6):794-802
为了探讨在氮饥饿对缺刻缘绿藻花生四烯酸(ArA)合成与积累的影响,通过cDNA末端快速扩增(RACE)和设计简并引物进行反转录(RT)-PCR扩增,克隆了编码该藻异质型乙酰辅酶A羧化酶(ACCase)的2个生物素羧基载体蛋白(BCCP)的基因序列。其中MiBCCP1基因的cDNA序列长1 267 bp,包含的5'-非翻译区(UTR)长44 bp,3'-UTR长524 bp,开放阅读框(ORF)长699 bp,编码232个氨基酸并含有45个氨基酸序列的叶绿体定位信号肽;预测成熟蛋白分子量约为20 ku。MiBCCP2基因的ORF长789 bp,编码263个氨基酸并含有49个氨基酸的叶绿体定位信号肽,推测成熟蛋白分子量约为22 ku,但其羧基端缺乏生物素酰基化位点。邻接法(NJ)构建的聚类图显示它们分属于2个不同的分支(靴带值为100)。采用半定量反转录(RT)-PCR技术分析这2个基因的表达量,结果显示,在氮饥饿光照培养条件下,它们的相对转录量都先短暂升高然后持续下调,从而表明缺刻缘绿藻脂肪酸的从头合成能力有下降的趋势。结合该藻的ArA含量在该培养条件下明显增加的结果,推测胞质中同质型ACCase对缺刻缘绿藻ArA合成与积累起着更重要的作用。  相似文献   

18.
The indispensable AA profile of fish carcass has been commonly used as a good indicator of fish amino acids requirements. Amino acid composition of the whole body tissue of Diplodus sargus was determined for the larval ages of 0, 2, 5, 8, 12, 17, 25, 35 and 45 days after hatching (DAH). No significant differences were found during this species ontogeny, except for phenylalanine. A comparative analysis of amino acid profiles from larvae and respective diet was performed. Low correlation was found to rotifers (R2 approximately 0.5), while higher correlations were found for Artemia nauplli, metanauplii (R2 approximately 0.8) as well as for the dry feed. These results suggest that D. sargus are subjected to higher nutritional imbalances during the first 10 days of feeding when larvae are fed on rotifers alone. Arginine, threonine, lysine, cysteine and histidine appeared to be limiting amino acids at 2, 12, 25 and 45 DAH, respectively. Similar results were reported in literature for Sparus aurata and Solea senegalensis, although D. sargus diets seem to have more amino acids in deficiency as well as more severe differences between larval and diet amino acid profiles. To solve these apparent nutritional imbalances, amino acid supplementation should be considered. The use of inert diets in early larvae ages seems to be most adequate as live feed supplementation appears to be more difficult.  相似文献   

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