共查询到20条相似文献,搜索用时 234 毫秒
1.
酪蛋白占牛奶总蛋白80%,具有很高的营养价值和重要的生理功能。A1和A2型β-酪蛋白是牛奶中两种主要的β-酪蛋白遗传变异体。牛奶A2型β-酪蛋白和人乳中的β-酪蛋白结构和消化特点相似,对人体更亲和,也更容易被消化吸收。开发A2型牛奶对增加乳制品品种、细分乳制品市场、提高乳制品档次具有积极意义。本文介绍了牛奶β-酪蛋白基因多态性、中国荷斯坦牛群β-酪蛋白基因型频率和等位基因频率、A2奶牛和A2牛奶的检测、以及A2乳制品开发现状,并对新疆开发A2牛奶及乳制品提出意见和建议。 相似文献
2.
《中国奶牛》2021,(9)
牛奶蛋白主要分为乳清蛋白和酪蛋白,其中酪蛋白的45%为β-酪蛋白,β-酪蛋白有两个主要的变异型,即A1型和A2型。为了解北京地区奶牛场A2型β-酪蛋白的分布情况,本研究采用PCR扩增牛β-酪蛋白(CSN2)部分基因片段后,用DdeⅠ对扩增产物进行酶切,建立了PCR-RFLP检测A2基因的方法。根据对北京地区155头荷斯坦公牛β-酪蛋白基因型检测的结果统计,A2A2基因型的种公牛大约占34.2%。之后通过对A2A2公牛家系进行血统分析,筛选出A2纯合型公牛后代女儿2 035头,并利用PCR-RFLP对这些奶牛个体进行A2基因型检测,发现1 137头A2A2纯合型个体。本研究为纯A2型β-酪蛋白牛群的选育提供了基础。 相似文献
3.
编码乳蛋白的基因位于常染色体上,呈共显性遗传.牛酪蛋白基因位于基因组第6号染色体上,编码4种酪蛋白的基因在染色体上的位置依次是αS1-酪蛋白、β-酪蛋白、αS2-酪蛋白和γ-酪蛋白,表明这4种酪蛋白基因的表达受到共同的启动元件和调控元件的调控[1].研究通过数字化差异显示技术分析发现,牛αS1-酪蛋白基因在牛泌乳前后的乳腺组织中的表达量发生着显著的变化,表明αS1-酪蛋白可能与牛的泌乳调控有关.因此,试验克隆了牛αS1-酪蛋白基因5′调控区域,并进行了多种生物信息学分析,现报道如下. 相似文献
4.
5.
奶牛被称为“人类的保姆”,牛奶是能为人类提供最优质、最完善的营养物质之一。而乳中蛋白质直接决定着乳制品的品质和风味。研究发现乳中蛋白质主要有两类:酪蛋白和乳清蛋白,两者占乳中蛋白质总量的95%,酪蛋白包括αS1,酪蛋白(αS1-CN)、αS2-酪蛋白(αS2-CN)、β-酪蛋白(β-CN)、 κ-酪蛋白(κ-CN);乳清蛋白包括α-乳清蛋白(α-La)、 相似文献
6.
牛乳总蛋白中酪蛋白约占80%,其中36%是β-酪蛋白。A1β-酪蛋白和A2β-酪蛋白是β-酪蛋白遗传变体中最常见的两种类型,A2β-酪蛋白为天然原型。A1β-酪蛋白和A2β-酪蛋白消化酶解后会产生不同的生物活性肽,来源于A1β-酪蛋白的BCM-7可能与1型糖尿病、心血管疾病、自闭症、精神分裂症、消化功能紊乱等人体慢性非传染性疾病的发生密切相关,A2β-酪蛋白酶解后产生的BCM-7要比A1β-酪蛋白少甚至不会产生β-酪啡肽-7(BCM-7)。β-酪蛋白基因多态性受常染色体上共显性基因控制,目前常用的检测方法为反相高效液相色谱法(RP-HPLC)、等电聚焦电泳(IEF)法和等位基因特异性聚合酶链式反应(AS-PCR)、单链构象多态性聚合酶链式反应(SSCP-PCR)等。文章对β-酪蛋白遗传变体A2β-酪蛋白功能特点、遗传学特点及A2β-酪蛋白基因检测方法进行综述,旨在为A<... 相似文献
7.
8.
9.
牛奶中蛋白质是生物活性肽的来源之一,这些肽在酪蛋白和乳清蛋白的消化过程中产生。因此,本试验主要研究牛奶中不同的κ-酪蛋白基因型A、B、C、E、F1、F2、G1、G2、H、I和J中活性肽对血管紧张素Ⅰ转换酶(ACE)抑制活性的影响。通过分析肛酪蛋白基因型的氨基酸序列来测定ACE抑制肽的活性。测定了已知的生物活性肽活力和其它一些κ-酪蛋白基因型巾其它肽的活性。结果表明,κ-酪蛋白基因型B和基因型C中的ASP(ACE抑制肽)的IC50(半数抑制浓度)值为242.3, 相似文献
10.
11.
本研究旨在了解生活在高海拔地区的藏黄牛乳的生化组成特点。试验测定了43头九龙藏黄牛乳蛋白含量、乳蛋白组成和酪蛋白多态性。藏黄牛乳蛋白含量低,仅约为29 g/L;电泳分析结果显示,脱脂乳蛋白组成与普通牛乳接近,主要包括酪蛋白、α-乳清蛋白和β-乳球蛋白等组分,β-Lg与α-La含量的比值低于牦牛;酪蛋白的相对含量约为70%,主要包含αs-CN和β-CN,二者分别检测到3和2种基因型。研究结果表明,九龙藏黄牛乳的组成与生活在类似生态环境中的九龙牦牛存在差异。 相似文献
12.
Barłowska J Litwińczuk Z Kedzierska-Matysek M Litwińczuk A 《Polish journal of veterinary sciences》2007,10(3):159-164
Polymorphism of goat milk alphas1-casein was determined and potential relations between genetic variants of this protein fraction and goat performance were evaluated. The investigations were performed on 598 goats assigned to of 4 breed groups (White improved 254 units, Coloured improved--124, White non-improved--146 and Coloured non-improved--74). For each goat, alphas1-casein polymorphism was determined in polyacrylamide gel by the PAGE-SDS method and percentage of milk alphas1-casein and gene frequency established. There was evaluated goat performance at successive lactations. In the goat population investigated, AA, AB, BB, AE, BE and EE alphas1-casein genotypes were identified. In all four breeds, alphas1-casein genotype EE clearly predominated (27.2-39.2%), recognized as "medium" and its share was higher in the groups of non-improved goats. It was conditioned by high frequency of gene E alphas1-casein (0.419-0.622). Generally, EE genotype percentage was higher in the non-improved goat groups. The improved goats, though, obtained higher productivity in each of the lactation studied. Analysis of relationships between alphas1-casein genetic variants and goats performance confirmed a significant influence on milk, protein and fat yields only in the Coloured improved goat group. There was revealed a more general tendency indicating a significant impact of "strong" alphas1-casein genotypes on a concentration of basic milk components, i.e. fat and protein, especially casein. In a group of goats producing milk of the highest casein content (over 2.4%) and protein (over 3.0%), the animals showing "strong" alphas1-casein variants dominated (85 and 70 %). 相似文献
13.
14.
Anna Wedholm Elin Hallén Lotte Bach Larsen Helena Lindmark-Månsson Anders Hans Karlsson Toomas Allmere 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(1):8-15
Abstract The milk composition in a Swedish herd, consisting of Swedish Red and White cows (SRB) and Swedish Holstein cows (SLB), and in a Danish herd, consisting of Danish Holstein-Friesian cows (SDM), was evaluated. Concentrations of the major milk proteins (κ-casein, αS1-casein, β-casein, β-lactoglobulin A, β-lactoglobulin B and α-lactalbumin) of 134 individual milk samples were determined by reversed phase (RP) HPLC. Other parameters determined included milk fat, urea, lactose, calcium, lactoferrin, somatic cell count and protein degradation (determined as level of free amino-terminals). Analysis of variance was used to compare concentrations of analysed milk variables between SRB and SLB or between SLB and SDM. Concentration of total protein, total casein, β-casein and κ-casein were significantly higher in SRB milk compared with SLB milk. Concentration of α-lactalbumin and calcium were significantly higher in SDM milk than in SLB milk. The concentration of urea was higher in SLB than in SDM milk and is suggested to reflect differences in feeding regimes between the investigated Swedish and Danish herd. 相似文献
15.
应用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和体外模拟消化研究羊乳蛋白质组成和消化特性。结果表明:羊乳蛋白质主要由酪蛋白和乳清蛋白组成,酪蛋白主要由αs1-酪蛋白、αs2-酪蛋白、β-酪蛋白和κ-酪蛋白组成,在酪蛋白中的相对含量分别为23.10%、30.39%、38.09%和8.42%;乳清蛋白主要由α-乳白蛋白、β-乳球蛋白、乳铁蛋白、血清白蛋白和免疫球蛋白组成,在乳清蛋白中的相对含量分别为24.59%、57.50%、4.35%、8.69%和4.88%;羊乳酪蛋白主要在肠液中消化,在胃液中消化120 min时 相似文献
16.
17.
18.
M Thymann 《Acta veterinaria Scandinavica》1972,13(4):539-553
The ϰ-casein content in milk from the Danish cattle breeds SDM, RDM and Jersey was investigated by means of immunoquantitation in antibody containing agarose gels. The method, which determines the total ϰ-casein complex, is suitable for routine work. The reproducibility of the method was found to be ± 4.1 %.The ϰ-casein concentration, expressed as percentage of the total protein content in milk, was significantly lower in milk from SDM (21.5%) and RDM (21.3%) than in Jersey (23.9%). The investigation showed that the ϰ-casein constitutes a greater part of the protein in milk than previously assumed.The amount of ϰ-casein was positively correlated with the protein content in milk, but there was no relation between the relative ϰ-casein content and the percentage of fat, milk yield and the time after calving.Keyword: kappa-casein, milk, cattle, immunoquantitation 相似文献
19.
本研究旨在分析中国水牛乳蛋白各亚型与乳蛋白粒径的关联。采用反向高效液相色谱法对160头泌乳中期的水牛进行多态性测定,并利用激光粒度仪分析水牛乳蛋白的粒径。结果显示:αs1-酪蛋白(αs1-CN)、β-酪蛋白(β-CN)和α-乳白蛋白(α-LA)存在A型和B型2种基因型,κ-酪蛋白(κ-CN)有A型、B型、C型和D型4种基因型,αs2-酪蛋白(αs2-CN)和β-乳球蛋白(β-LG)没有发现多态性。κ-CN和αs1-CN各亚型在乳蛋白面积平均径(D[3,2])上有显著差异,筛选出的6种αs1-β-κ-CN复合基因型在乳蛋白面积平均径(D[3,2])以及中位径(D50)上差异显著。综上,水牛αs1-β-κ-CN复合基因为AB-BB-AB型以及κ-CN的C等位基因均与乳蛋白粒度存在显著关联。 相似文献