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乳铁蛋白的营养生理作用及其作为饲料添加剂的应用 总被引：3，自引：0，他引：3
对乳铁蛋白的乳铁蛋白活性多太的结构及其动物体内的分布进行了分析，重点阐述了它们促进肠道铁离子的吸收，调节机体免疫机能，抑菌和抗菌活性，抗病毒，抗氧化，刺激肠道有益菌群生长，保护肠道等多种生理功能，总结了乳铁蛋白的测定方法，讨论了利用天然初乳制备乳铁蛋白和乳铁蛋白活性肽的的工艺和利用基因工程生产乳铁蛋白和乳铁蛋白活性肽。对乳铁蛋白和乳铁蛋白活性肽在饲料加工过程及动物肠道中的稳定性进行了分析，并初步讨论了乳铁蛋白和乳铁蛋白活性肽代替饲用抗生素作为饲料添加剂的应用前景。 相似文献
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乳铁蛋白生理功能研究现状 总被引：10，自引：0，他引：10
乳铁蛋白是一种具有多种生理功能的铁结合糖蛋白。本文阐述了乳铁蛋白促进铁吸收、调节免疫、抗菌、抗病毒、阻断氧自由基和促进双歧杆菌生长等生理功能，并对其应用前景进行了展望。 相似文献
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乳铁蛋白是一种铁结合性糖蛋白,具有抗菌、抗病毒、抗肿瘤、免疫调节等多种生理功能,在食品、医药、饲料和化妆品等领域具有非常广阔的应用前景.作者对乳铁蛋白的免疫作用进行了研究,结果证明乳铁蛋白可以提高疫苗的免疫效果,具有较好的免疫佐剂作用. 相似文献
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乳铁蛋白是一种人体必不可缺,存在于人体液中的蛋白质,能参与机体免疫调节,增强机体抗病能力,同时对铁的结合力是转铁蛋白家族中最强的。乳铁蛋白本身具有抗病毒能力,但和过氧亚硝酸盐相结合会降低其抗病毒能力。基于不同哺乳动物自身乳铁蛋白的机理及其发展状况、未来应用前景、自身检测方法等进行详细地阐述。 相似文献
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乳铁蛋白肽具有杀菌、抗病毒、抗真菌等多种独特的生物学活性。综述了乳铁蛋白肽的结构、生物学功能、国内外研究动态及其应用前景,提出了其研究中存在的问题及相应对策。 相似文献
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乳铁蛋白肽的研究进展 总被引：12，自引：0，他引：12
乳铁蛋白肽(Lactoferricin,Lfcin)是动物乳汁中的乳铁蛋白(Lactoferrin,LF)在动物消化道中经酸性胃蛋白酶降解后产生的含25～28个氨基酸的小肽,它具有杀菌、抗病毒、抗真菌等多种独特的生物学活性,对动物具有保护功能.本文概述了乳铁蛋白肽的结构、生物学功能、国内外研究动态及其应用前景. 相似文献
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利用PCR技术从高原牦牛基因组DNA中获得了乳铁蛋白素(lactoferricin,Lfcin)基因序列;将Lfcin基因连接于pGEM T easy载体,送至生物公司测序;将高原牦牛与奶牛的Lfcin基因序列进行比对;同时,对牦牛、奶牛、人、小鼠等物种的Lfcin蛋白序列进行分析。结果表明：克隆获得了含高原环湖牦牛LF(lactoferrin)第2外显子的DNA序列,共778 bp,其中Lfcin基因编码区长75 bp,编码25个氨基酸; 序列分析显示,克隆获得的牦牛DNA序列与奶牛这一序列存在9个碱基的变异;牦牛和奶牛的Lfcin蛋白质序列完全相同,各物种Lfcin蛋白具有较高的同源性。 相似文献
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近年来,随着对乳铁蛋白和乳铁蛋白肽作用机制和空间结构的研究趋于成熟,国内外研究者逐渐将研究重点倾向于乳铁蛋白和乳铁蛋白肽的开发应用.主要介绍了乳铁蛋白和乳铁蛋白肽基因工程的研究进展,尤其是对原核表达系统和真核表达系统进行了综述. 相似文献
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Omata Y Satake M Maeda R Saito A Shimazaki K Yamauchi K Uzuka Y Tanabe S Sarashina T Mikami T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(2):187-190
Sporozoites of Toxoplasma gondii preincubated with lactoferricin showed decreased activity in penetration of mouse embryonal cells. Mice inoculated with 10(5) sporozoites preincubated with lactoferricin showed a higher survival rate than those inoculated with the same number of untreated sporozoites. Likewise, sporozoites of Eimeria stiedai preincubated with lactoferricin also showed decreased activity in penetration of rabbit hepatobiliary cells. Rabbits inoculated with 10(5) sporozoites preincubated with lactoferricin shed fewer oocysts than those inoculated with the same number of untreated sporozoites. These results indicate that lactoferricin is effective to reduce the infectivity of sporozoites of Toxoplasma gondii and Eimeria stiedai. 相似文献
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OBJECTIVE-To design short and potent analogs of bovine lactoferricin by use of the concepts of lipophilic bulk and cationic charge. SAMPLE POPULATION-5 synthetic peptides of bovine lactoferricin. PROCEDURE: Antibacterial peptides were constructed by synthesizing several decapeptides rich in arginine and tryptophan. Basic residues of bovine lactoferricin (bLf 20-29; residues 20 to 29) were modified by substitution with arginine or lysine and nonbasic residues were modified by substitution with tryptophan, phenylalanine, or isoleucine. Synthetic peptides of bovine lactoferrin (LFB) were designated as LFB-RW (RRWWWRWRRW), LFB-KW (KKWWWKWKKW), LFB-RWa (RRWWRRWRRW), LFB-RF (RRFFFRFRRF), and LFB-RI (RRIIIRWRRI), where R, K, W, F, and I stand for arginine, lysine, tryptophan, phenylalanine, and isoleucine, respectively. Peptides were evaluated by determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis. RESULTS: LFB-RW, LFB-KW, and LFB-RWa possessed equivalent potency as bLf 20-29 against E coli. LFB-RW and LFB-RWa had a 2-fold increase in growth-inhibitory and bactericidal activity against S aureus, compared with bLf 20-29. LFB-RI had the lowest MIC value against E coli among the peptides but lost bactericidal activity. LFB-RW and LFB-KW had stronger bactericidal activities against S aureus or E faecalis, respectively, as well as E coli than the other synthetic peptides. LFB-RF also had antibacterial activity, but this was 2-fold less than that of LFB-RW, as determined by MIC and MBC values. CONCLUSIONS AND CLINICAL RELEVANCE: In construction of potent antibacterial peptides, inclusion of arginine, lysine, tryptophan, or isoleucine residues enhances effectiveness against certain bacteria, as measured by MIC or MBC values. 相似文献
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Antimicrobial, anti-inflammatory and immunomodulating properties of lactoferrin have been demonstrated in mammals and in fish. However, in vivo, lactoferrin is digested by gastric pepsin treatment into the N-terminal derived peptide named lactoferricin. This has been so far overlooked in fish in vitro studies. The aim of the present study was to assess in vitro the effects of both lactoferricin and lactoferrin on the head kidney cells of European sea bass (Dicentrarchus labrax, L.) in order to determine their potential as dietary additives and to get some insight into their mode of action. In vitro lactoferricin decreased significantly the chemiluminescent response of head kidney cells but did not affect the zymosan-triggered chemiluminescence activity. On the other hand, a high concentration of lactoferrin directly stimulated chemiluminescence but reduced the zymosan-triggered chemiluminescence. The bactericidal activity of head kidney cells was also significantly diminished by pre-incubation with lactoferrin in a dose-dependent manner. Although no significant effect of lactoferricin or lactoferrin was evidenced on head kidney cellular viability, absent or negative effect on the priming of respiratory burst activity suggested that care should be taken when using lactoferrin in the diet of sea bass and high doses should be avoided. Hypotheses about the mechanisms of action of lactoferricin and lactoferrin are presented. 相似文献
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On account of the oxidative stress conditions that may appear during parturition, colostrum should provide with not only nutritional and immunological components but also antioxidative protection of newborn. There is evidence that apart from well-known antioxidative enzymes like glutathione peroxidase, superoxide dismutase, catalase or low molecular antioxidants, proteins like lactoperoxidase (LPO), lactoferrin (LF) and ceruloplasmin (CP) may exert antioxidative properties in colostrum. The aim of present study was to determine and to evaluate LPO, LF and CP activities in colostrum and milk of sows and cows. Samples were collected from 16 healthy cows five times: immediately after parturition, 12, 24 and 48 h, and 7 days postpartum as well as from 14 healthy sows five times: immediately after parturition, 6, 12, 24 and 36 h later. Examined parameters were determined spectrophotometrically at 412, 560 and 540 nm respectively. LPO activity was higher in sows as in cows and increased significantly within examined time. LF ability to inhibit superoxide radical generation was higher in sows as in cows and increased significantly within examined time. CP oxidase activity was higher in cows as in sows and decreased significantly during experimental period. In conclusion, antioxidative defence system in colostrum shows dynamic changes that allow for providing with necessary protection from oxidative stress conditions, which may appear after parturition. 相似文献
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抗菌肽与抗生素的体外抗菌效果比较 总被引：17，自引：0，他引：17
应用由 Hancock实验室改进的微量肉汤稀释法测定了 cecropin P1、cecropin A、magainin 2、defensin 1、bactenecin、lactoferricin和 indolicidin等 7种抗菌肽和盐酸金霉素、去甲万古霉素、土霉素、强力霉素等 4种抗生素的体外抗菌活性 ,并且使用薄层琼脂糖孔穴扩散法比较了抗菌肽中 cecropin P1和 cecropin A与土霉素和呋喃唑酮对大肠杆菌 K88的抑菌效果。结果发现 ,抗菌肽与抗生素一样对几种革兰氏阳性菌和阴性菌都有不同程度的抗菌效果。其中 cecropin A、cecropin P1和 defensin1对大肠杆菌的 2个菌株 ATCC2 5 92 2和 K88的抗菌活性高于抗生素 ,defensin1是各种抗菌肽中对金黄色葡萄球菌抗菌效果最好的。抗生素对试验用金黄色葡萄球菌的抑制活性总体上要好于抗菌肽。与抗生素相比 ,cecropin A、cecropin P1和 indolicidin对猪霍乱沙门氏菌和鼠伤寒沙门氏菌具有更好的抗菌效果。另外 ,抗菌肽的抑菌圈边缘十分清晰 ,而抗生素的整个抑菌圈都比较模糊且界线不明。因此 ,从抗菌效果方面考虑 ,抗菌肽可以代替抗生素用于疾病的预防和治疗 相似文献
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1. The influence of the flicker frequency on physical activity and energy expenditure of broilers was studied using commercially available high-frequency (HF) and low-frequency (LF) fluorescent lamps in a 23L:1D lighting schedule. 2. Broilers were reared under and adapted to HF. They were alternately subjected to HF and LF during measurement of activity and energy expenditure. 3. In comparison with HF, LF inhibited activity (number and intensity of movements), but did not influence energy expenditure. 4. It was concluded that the 100 Hz flickering of low-frequency light is detected by broilers and has measurable behavioural effects upon them. 5. The results were discussed in relation to current knowledge of human and birds' critical flicker frequency and perception. 相似文献