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1.
African trypanosomes, the cause of sleeping sickness, need massive amounts of myristate to remodel glycosyl phosphatidylinositol (GPI) anchors on their surface glycoproteins. However, it has been believed that the parasite is unable to synthesize any fatty acids, and myristate is not abundant in the hosts' bloodstreams. Thus, it has been unclear how trypanosomes meet their myristate requirement. Here we found that they could indeed synthesize fatty acids. The synthetic pathway was unique in that the major product, myristate, was preferentially incorporated into GPIs and not into other lipids. The antibiotic thiolactomycin inhibited myristate synthesis and killed the parasite, making this pathway a potential chemotherapeutic target.  相似文献   

2.
An unusual form of lipid linkage to the CD45 peptide   总被引：1，自引：0，他引：1  
Some protein kinases and phosphatases are myristoylated on their amino terminus, which perhaps contributes to subcellular localization or regulation. Glycoprotein CD45, a hematopoietic tyrosine phosphatase, was examined for fatty acid content. The CD45 protein incorporated [3H]myristate, but little [3H]palmitate. The label was not metabolized and reincorporated into amino acids or saccharides, as revealed by peptide maps of CD45 labeled with [3H]myristate, 14C-labeled amino acids, [35S]methionine, or 125I, and glycosidase treatments, respectively. The myristate label was resistant to mild alkaline methanolysis and was found in fatty acid and sphingosine, indicating an unusual form of lipid attachment to CD45.  相似文献   

3.
A primary intracellular substrate for pp60v-src kinase in a variety of avian and mammalian cells is a protein of 34 to 39 kilodaltons (kD). After incubation of chicken embryo fibroblasts (CEF) with [3H]myristic acid for 4 hours, the 36-kD protein contained covalently bound myristic acid by several criteria: (i) the radioactively labeled material comigrated with the 36-kD protein on sodium dodecyl sulfate-polyacrylamide gels in one and two dimensions, (ii) the labeled material was insoluble in chloroform-methanol, and (iii) radioactively labeled myristate could be recovered from the purified 36-kD protein. The resistance of the acyl fatty acid moiety to hydrolysis by hydroxylamine suggested that the covalent linkage to the 36-kD protein may be through an amide linkage. The [3H]myristic-acid labeling of the 36-kD protein in Rous sarcoma virus-transformed CEF showed a reduction of up to 45 percent when compared to an identical amount of 36-kD protein derived from normal cells; this reduction was not due to general changes in myristic acid metabolism in transformed cells.  相似文献   

4.
[目的]分析测定阿魏菇中的脂肪酸类化学成分。[方法]采用气质联用法对索氏提取和超声波提取的阿魏菇脂肪酸的化学组成及含量进行了测定分析。[结果]索氏提取与超声波提取的阿魏菇脂肪酸的主要成分基本一致,但索氏提取的阿魏菇脂肪酸的不饱和脂肪酸含量比例较高。气质检测结果表明：索氏提取与超声波提取的阿魏菇脂肪酸的均含有十四烷酸甲酯（肉豆蔻酸甲酯）、十五烷酸甲酯、十六烷酸甲酯（棕榈酸甲酯）、十八碳二烯酸甲酯（亚油酸甲酯）、十八碳烯酸甲酯（油酸甲酯）、十八烷酸甲酯（硬脂酸甲酯）,索氏提取阿魏菇脂肪酸各组分的相对含量分别为0.43%、2.76%、14.84%6、3.41%、2.10%、16.46%1、6.46%,超声波提取阿魏菇脂肪酸各组分的相对含量分别为0.32%、2.49%、12.73%6、1.53%1、.14%、21.78%、21.78%。[结论]索氏提取法是一种较好的阿魏菇脂肪酸的提取方法。  相似文献   

5.
大米小包装储藏过程中脂类及微观结构的变化   总被引：1，自引：1，他引：0  
【目的】由于胚乳失去保护,大米在储藏过程中易发生陈化、霉变等问题,致使其品质劣变甚至丧失食用价值。通过测定储藏过程中大米游离脂肪酸、总酸含量、脂肪酸组成和含量,观察大米横断面胚乳细胞、淀粉颗粒微观结构,探讨大米品质劣变原因,为大米储藏技术提供参考。【方法】以粳稻99号大米为对象,进行人工模拟储藏试验：采用编织袋、自然密闭缺氧、抽真空3种包装方式,置于温度为15、25和30℃（60%湿度）的人工气候箱中储藏180 d,每个月进行一次品质指标测定;测定大米储藏过程中脂肪酸值、总酸值的变化,利用气相色谱分析脂肪酸组成及含量变化,利用扫描电镜观察大米横断面胚乳细胞形态,探索脂类及横断面胚乳结构导致大米品质陈化的机理及品质劣变后淀粉颗粒微观形态的变化规律。【结果】①储藏过程中,编织袋及自然密闭缺氧包装的大米游离脂肪酸及总酸含量皆呈现急剧上升趋势,当品质劣变严重时两者含量反而下降;抽真空包装的大米游离脂肪酸及总酸含量均保持在较稳定的水平,且储藏温度对其含量影响不显著;②脂肪酸组成中含量最多的是亚油酸、油酸和棕榈酸,这3种脂肪酸含量占总脂肪90%以上。包装方式及储藏温度对各脂肪酸组成影响不同。除了花生酸（C20:0）及二十二烯酸（C22:1）外,其余脂肪酸受包装方式影响较大;而储藏温度仅与豆蔻酸（C14:0）和山嵛酸（C22:0）有显著性关系,对其余脂肪酸影响不大。脂肪酸变化规律符合：高不饱和脂肪酸含量随温度升高而降低,多不饱和脂肪酸与饱和脂肪酸及单不饱和脂肪酸间呈现显著负相关,具体表现为硬脂酸（C18:0）与亚油酸（C18:2）、亚麻酸（C18:3）;油酸（C18:1）与亚油酸、亚麻酸皆呈现明显的“此消彼长”现象。③新鲜大米淀粉粒以复粒形式存在,形状较大,表面有较厚的膜,排列整齐有序,两侧以片状的细胞间断面居多,放射状结构清晰可见。陈化加剧的大米胚乳细胞横断面结构松散无序,细胞内断面多于细胞间断面,横断面上可观测到“小孔”及一些分散在淀粉体周围的蛋白体和脂肪滴;细胞壁的完整性受到破坏致使复粒崩解并可见大量单粒细胞,一部分单淀粉粒形状近圆型,棱角较钝;细胞间的棱角模糊,放射状结构变得模糊甚至消失。【结论】编织袋及自然密闭缺氧包装的大米陈化劣变较为严重,储藏过程中其脂肪酸值、总酸值急剧上升后下降,胚乳表面光滑度变差、小孔数量及表面蛋白质膜的翘起变多,辐射状趋势渐渐消失。抽真空包装可以有效延缓大米品质劣变进程。  相似文献   

6.
The feeding trial was conducted to determine the effects of flaxseed on layer's performance and egg quality,and the effects of the dietary ratio of ω-6 fatty acid to ω-3 fatty acid on fatty acid deposition in yolk using flaxseed as resource of ω-3 fatty acid and sunflower seed as resource of ω-6 fatty acid.192 20-wk-old Newroman commercial hens were randomly divided into 4 treatment groups with 6 replicates containing 8 birds.The rations corresponding with the four treatments were formulated with 4% flaxseed + 9% sunflower seed,8% flaxseed + 18% sunflower seed,15% flaxseed,and soybean meal,respectively.Sunflower seed was unshelled and flaxseed was whole.Ratios of to-6 fatty acid to ω-3 fatty acid in 4 dietary treatments were 5.67,5.21,1.07,and 11.83,respectively.It can be concluded that long-term feeding 15% flaxseed had no significant(P＞0.05)influence on egg production,egg weight,eggshell quality,yolk weight,and percentage of yolk weight.Dietary ratio of ω-6 fatty acid to ω-3 fatty acid had impact on the ω-3 fatty acid levels in yolk,nevertheless yolk fatty acid profiles were different from those of dietary fatty acid compositions.  相似文献   

7.
Soybean Dongnong 42 from northeast of China was used as an experimental material. The samples were tested by spraying different concentrations of LaCl3, CeCl3 and LaCl3+CeCl3 solutions on the leaves at the seedling stage and the early flowering stage of the soybeans. Gas chromatography was used to determine the fatty acid content and ratio of the soybean seeds at the maturity stage. The fatty acid ratio of soybean seeds were evaluated by calculating saturated fatty acid(SFA), monounsaturated fatty acid(MUFA), polyunsaturated fatty acid(PUFA), unsaturated fatty acids(UFA), UFA/SFA, index unsaturated fatty acid(IUFA) and double bond index(DBI).(MUFA+PUFA)/SFA was used to study the effects of rare earths on the quality of soybean seeds. The results showed that spraying the rare earth solution could significantly optimize the fatty acid distribution ratio of soybean seeds. Compared with the control group(CK), stearic acid was reduced by 5% and linolenic acid was reduced by 3.72%. Except for La10, the oleic acid content increased significantly by 2.22%. Under the treatment of 30 mg·L~(-1) CeCl_3, UFA, UFA/SFA and DBI were 83.56, 5.08 and 9.47, respectively, which were the highest in each group. Under the treatment of 150 mg·L~(-1) LaCl_3,(MUFA+PUFA)/SFA was 4.89, the closest meal to the recommended ratio. The above results showed that spraying appropriate concentrations of rare earth at the seedling stage and the early flowering stage could optimize the fatty acid ratio of soybean seeds and improve dietary fatty acid ratios.  相似文献   

8.
The feeding trial was conducted to determine the effects of flaxseed on layer＇s performance and egg quality, and the effects of the dietary ratio of ω-6 fatty acid to ω-3 fatty acid on fatty acid deposition in yolk using flaxseed as resource of ω-3 fatty acid and sunflower seed as resource of ω-6 fatty acid. 192 20-wk-old Newroman commercial hens were randomly divided into 4 treatment groups with 6 replicates containing 8 birds. The rations corresponding with the four treatments were formulated with 4% flaxseed ＋ 9% sunflower seed, 8% flaxseed ＋ 18% sunflower seed, 15% flaxseed, and soybean meal, respectively. Sunflower seed was unshelled and flaxseed was whole. Ratios of ω-6 fatty acid to ω-3 fatty acid in 4 dietary treatments were 5.67, 5.21, 1.07, and 11.83, respectively. It can be concluded that long-term feeding 15% flaxseed had no significant （P〉 0.05） influence on egg production, egg weight, eggshell quality, yolk weight, and percentage of yolk weight. Dietary ratio of ω-6 fatty acid to ω-3 fatty acid had impact on the 0-3 fatty acid levels in yolk, nevertheless yolk fatty acid profiles were different from those of dietary fatty acid compositions.  相似文献   

9.
烤烟有机酸含量的杂种优势表现及亲子相关分析   总被引：1，自引：0，他引：1  
研究了48个烤烟F1组合的杂种优势表现及其与亲本之间的相关关系.结果表明:(1)非挥发性有机酸、高级脂肪酸以及有机酸总量均存在较强的杂种优势.中亲优势大小依次为不饱和高级脂肪酸(16.30%),饱和高级脂肪酸(12.39%),有机酸总量(5.61%),非挥发性有机酸(2.88%);超亲优势大小表现出与中亲优势相同,其中非挥发性有机酸及有机酸总量为负向超亲优势,但仍有部分组合表现出正向超亲优势;(2)亲子相关分析表明,高级脂肪酸含量同时受中亲值和低亲值的显著影响,而非挥发性有机酸与有机酸总量受双亲影响不显著.杂种优势间的相关分析结果表明,除非挥发性有机酸外,其他有机酸的杂种优势之间均存在极显著相关关系.  相似文献   

10.
雌性阿根廷滑柔鱼性腺发育阶段的脂肪酸组成及其变化   总被引：2，自引：2，他引：0  
阿根廷滑柔鱼是典型的头足类,资源生物量与其生长发育过程中营养物质积累及生殖投入密切相关。为了获知雌性阿根廷滑柔鱼性腺发育各阶段的脂肪酸组成及其变化特点,研究采用氯仿甲醇法和气相色谱法检测分析胴体、消化腺和卵巢的脂肪酸种类及其含量。结果表明,雌性阿根廷滑柔鱼胴体、消化腺和卵巢3个组织的脂肪酸均以多不饱和脂肪酸(PUFA)为主,饱和脂肪酸(SFA)次之,单不饱和脂肪酸(MUFA)的总含量最低。胴体组织的脂肪酸种类最全面,共检测出28种脂肪酸,消化腺和卵巢分别检测出21种和17种脂肪酸。检测发现3个组织中SFA均以C16∶0脂肪酸最为丰富,MUFA以C18∶1n9c和C20∶1脂肪酸为主,PUFA的DHA(C22∶6n3)最丰富,EPA(C20∶5n3)次之。胴体的SFA和MUFA在成熟期达到最大值,在产卵期显著降低;消化腺的PUFA保持相对稳定水平,但是其含量显著低于胴体和卵巢;卵巢持续积累脂肪酸,在产卵期时MUFA和PUFA显著降低。研究表明,雌性阿根廷滑柔鱼胴体、消化腺和性腺3个组织的脂肪酸种类具有组织特殊性,而主要脂肪酸具有一致性。性腺发育过程中,胴体的SFA和MUFA可能转化为能量供给卵巢发育,消化腺的PUFA则向胴体和卵巢转移,卵巢则持续积累脂肪酸供给卵子发生。  相似文献   

11.
为了解不同番茄样品内种子脂肪酸的组成含量差异,采用索氏提取法提取6个番茄种子样品中的粗脂肪,用 KOH‐甲醇溶液对脂肪酸进行甲酯化,以37种脂肪酸组分标品为对照,采用气相色谱分析法测定其脂肪酸含量及组成.结果表明:番茄种子干物质平均含量为52.48%,粗脂肪平均含量为32.82%;番茄种子样品间脂肪酸总量有一定差异;番茄种子脂肪酸组分相对百分含量有一定差异,其主要脂肪酸组成及含量为棕榈酸11.16%~12.54%、硬脂酸3.82%~5.12%、油酸17.32%~29.85%、亚油酸52.63%~64.12%、α‐亚麻酸1.45%~2.17%.  相似文献   

12.
饲料中植物油替代鱼油对中华绒螯蟹脂肪酸组成的影响   总被引：2，自引：2，他引：0  
为研究饲料中植物油替代鱼油对中华绒螯蟹脂含量及脂肪酸组成的影响,采用植物油[m(豆油)∶m(菜籽油)=3∶1]替代不同水平(0%、50%和100%)的鱼油,制成3种等氮等脂饲料(F1、F2和F3)喂养3组成体雌蟹70 d。结果显示,3组蟹的体肉、性腺和肝胰腺的粗脂肪含量无显著性差异(P0.05)。各组饲料的脂肪酸组成有所不同,体肉中多不饱和脂肪酸(polyunsaturated fatty acid, PUFA)占比约50%,其含量无显著性差异(P0.05);性腺中n-6 PUFA含量随着替代水平的升高而升高;肝胰腺受饲料中植物油替代鱼油的影响最大,单不饱和脂肪酸(monounsaturated fatty acid, MUFA)及PUFA总含量都随着替代水平的升高而升高;与F1、F3组相比,F2组3个可食部位的EPA+DHA含量均较高。综上所述,使用50%植物油替代鱼油饲料喂养雌性中华绒螯蟹对其可食部位的脂肪酸组成有正面作用。本研究为优化育肥饲料中鱼油替代源配比以及进一步改善中华绒螯蟹品质等提供了一定的依据。  相似文献   

13.
苹果膜脂脂肪酸与冻害关系的研究   总被引：1，自引：0，他引：1  
苹果枝条皮部所含膜脂脂肪酸的种类相同,主要有亚油酸(18∶2)、亚麻酸(18∶3)和软脂酸(16∶0),其次是油酸(18∶1)和硬脂酸(18∶0);但不同品种脂肪酸种类配比各异.各种脂肪酸的克分子百分比含量随着季节的变化而变化,不饱和度高的脂肪酸(18∶2和18∶3)在冷凉和寒冷的季节中明显高于温暖季节,而饱和脂肪酸(16∶0和18∶0)和饱和度低的脂肪酸(18∶1)则与此完全相反.另外,不饱和脂肪酸的克分子百分含量与苹果的冻害级别(抗寒力)显著相关,因此膜脂不饱和脂肪酸的克分子百分比含量可以作为抗寒力鉴定的指标.  相似文献   

14.
[目的]探讨盐胁迫下水稻幼苗类囊体膜脂肪酸组分变化。[方法]6叶1心的水稻幼苗在不同浓度NaCl胁迫不同时间后用于提取类囊体膜脂肪酸,并用1890气相色谱仪分析脂肪酸组分。[结果]随着NaCl胁迫浓度增加和时间的延长,2个供试材料Pokkali和Peta水稻类囊体膜14∶0,18∶0,16∶1(3t),18∶1脂肪酸组分含量在前4 d变化不大,之后略为上升;Pokkali和Peta的16∶0、饱和脂肪酸含量(LS-FA)前4 d变化也不大,之后Pokkali的明显上升,而Peta的呈下降趋势;Pokkali和Peta的18∶3组分和不饱和脂肪酸指数(IUFA)一直下降,100 mmol/L较200 mmol/L NaCl处理下降幅度小,且在相同的条件下,Pokkali较Peta的下降幅度小;而Pokkali和Peta的饱和度水平上升,且Peta上升幅度较Pokkali小。[结论]在不饱和脂肪酸指数方面,Pokkali较Peta耐盐。  相似文献   

15.
尿素包合法富集红松子油脂肪酸成分分析   总被引：1，自引：0，他引：1  
采用尿素包合法(液料比为m(脂肪酸)∶V(乙醇)=1 g∶12 mL,m(脂肪酸)∶m(尿素)=1.0∶1.5),将红松子油中的皮诺敛酸进行富集纯化;利用气相色谱-质谱(GC-MS)分析富集后混合脂肪酸中各个成分质量分数。结果表明:经尿素包合法富集后的混合脂肪酸中,皮诺敛酸(C18∶3)甲酯质量分数最高达到45.8%,其次亚麻酸质量分数为16.32%、亚油酸质量分数4.88%。经纯化富集后的脂肪酸收率虽然较低,但对人体有益的多不饱和脂肪酸质量分数明显增加。  相似文献   

16.
以5个沙棘(Hippopha觕rhamnoides L.)品种的果实为试材,建立气相色谱内标法测定沙棘果肉油和种子油主要脂肪酸成分的方法。果肉油和种子油采用氯仿-甲醇法提取,甲醇钠-甲醇法甲酯化衍生后进行定性和定量。结果表明,十九烷酸甲酯是气相色谱法测定沙棘果实中脂肪酸成分含量的理想内标物。果肉油和种子油中的主要脂肪酸为棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸和α-亚麻酸。果肉油中棕榈油酸(36.25%)和棕榈油酸(28.92%)含量高,α-亚麻酸含量低;种子油中亚油酸(33.65%)和α-亚麻酸(32.95%)含量高,棕榈油酸含量低。5个品种沙棘的果肉油和种子油中主要脂肪酸的组成及含量存在一定的差异。亚历山大12号果肉油中的脂肪酸含量最高,为84.84 g/100 g油;无刺丰种子油中的脂肪酸含量最高,为88.39 g/100 g油。该方法操作简便、快速、重复性好,适合沙棘油脂样品中脂肪酸的定量测定。  相似文献   

17.
[Objective] The aim of the study is to understand the changes of fatty acid composition of rice thylakoid membrane under salt stress.[Method] Under salt stress of different concentrations of NaCl,rice seedlings of Pokkali and Peta with six leaves and one central leaf were used as experimental materials to extract the fatty acid from their thylakoid membranes,and gas chromatograph(1890)was used to analyze fatty acid composition.[Result] Fatty acid component 14∶0,18∶0,16∶1(3t),18∶1 in both the two experimental materials showed little variations in the first four days of salt stress,whereafter they increased slightly;while the fatty acid component 16∶0 and level of saturation of fatty acid(LSFA)showed the similar variation trend in the first four days of treatment compared to those of the fatty acid components mentioned above,whereafter they rose in Pokkali and presented an opposite variation trend in Peta;fatty acid component 18∶3 and level of unsaturation of fatty acid(LUFA)reduced all the time under stress condition,and the reducing amplitude in 100 mmol/L NaCl treatment group was smaller than that of 100 mmol/L NaCl treatment group,and in Pokkali was smaller than that in Peta under specific conditions.Meanwhile,level of saturation of fatty acid in both experimental materials increased,and the rising amplitude in Peta was smaller than that of Pokkali.[Conclusion] With regard to LUFA,Pokkali is endowed with more salt tolerance than Peta.  相似文献   

18.
【目的】 大豆（Glycine max）原产于中国,高品质的大豆在食品、饲料、纺织品等多种加工业中广泛应用,因此,选育高品质大豆已成为育种者和生产者的聚焦问题。通过对大豆脂肪酸各组分进行QTL定位及候选基因的筛选,为大豆品质改良奠定分子基础。【方法】 以美国大豆品种Charleston和东农594为亲本构建重组自交系（RILs）、以栽培大豆绥农14与野生大豆ZYD00006为亲本构建染色体片段代换系（CSSLs）为试验材料。利用气相色谱法测定2个群体的脂肪酸含量,根据东北农业大学农学院大豆遗传改良实验室已构建的遗传图谱,通过Windows QTL Cartographer 2.5和ICIMapping软件对2017—2018年RIL群体与CSSL群体中的大豆脂肪酸组分进行QTL定位研究,并对所获得的QTL置信区间进行候选基因的挖掘。【结果】 2017—2018年,RIL群体和CSSL群体分别定位到34和20个与脂肪酸组分相关的QTL,分布在除B2、C1、G、H、J、M和O以外的13个连锁群上。比较2个群体的QTL定位结果,发现在2个群体中重复检测到10对QTL,其中,分布在A1、C2、D1a、F、K和N连锁群上的QTL与多种脂肪酸含量相关,在A1连锁群上检测到亚油酸和油分含量重叠的QTL;在C2连锁群上检测到硬脂酸和油分含量重叠的QTL;在D1a连锁群上检测到硬脂酸和油分含量重叠的QTL;在F连锁群上检测到棕榈酸、硬脂酸和油分含量重叠的QTL;在K连锁群上检测到亚油酸和亚麻酸含量重叠的QTL;在N连锁群上检测到棕榈酸和油分含量重叠的QTL、油酸和亚油酸含量重叠的QTL。对QTL定位获得的所有置信区间进行候选基因的挖掘,从基因注释数据集中共筛选出485个候选基因,其中,271个候选基因具有GO注释,进一步进行GO富集数据分析,共有15个候选基因与脂肪酸相关。主要通过编码植物酰基-酰基载体蛋白（ACP）硫酯酶、脂肪酸去饱和酶、磷脂酶D1、脂肪酸-羟化酶、丙酮酸激酶和参与酰基辅酶A生物合成、调节脂肪酸链的延伸,从而影响脂肪酸的合成。【结论】 共检测到54个与大豆脂肪酸各组分相关的QTL,在2个群体中重复检测到10对QTL,对QTL定位获得的置信区间进行候选基因的筛选,共有15个候选基因与脂肪酸相关。这些稳定的脂肪酸相关的QTL和脂肪酸相关的候选基因可用于大豆脂肪酸改良的分子标记辅助选择。  相似文献   

19.
Intramuscular fat (IMF) content is considered to be a key factor that affects the marbling, tenderness, juiciness and flavor of pork. To investigate the effects of myristic acid (MA) on the differentiation of porcine intramuscular adipocytes, cells were isolated from longissimus dorsi muscle (LDM) and treated with 0, 10, 50 or 100 μmol L-1 MA. The results showed that MA significantly promotes the differentiation of intramuscular adipocytes in a dose-dependent manner. MA also led to a parallel increase in the expression of peroxisome proliferator activated receptor-γ (PPARγ) and adipose-related genes, such as glucose transporter 1 (GLUT1), lipoprotein lipase (LPL), adipocyte fatty acid binding protein 4 (FABP4/aP2), fatty acid translocase (FAT), acetyl-CoA carboxylase α (ACCα), adipose triglyceride lipase (ATGL) and fatty acid synthase (FASN). However, no significant effects of MA were observed on the expression of CAAT enhancer binding protein-α (C/EBPα) or hormone sensitive lipase (HSL). The expression of pyruvate dehydrogenase kinase 4 (PDK4) was increased by MA during the early stages of differentiation (day 1-3). In addition, MA also increased the absolute content of C14 (P<0.001) and saturated fatty acids (SFA) (P<0.05) to varying degrees, but no effects were observed on other fatty acids. These results suggest that MA might be able to enhance the IMF content of pork and increase the accumulation of myristic and myristoleic acid in muscle, which might have beneficial implications for human health.  相似文献   

20.
缺刻缘绿藻（Myrmecia incisa Reisigl）是一种富含多不饱和脂肪酸的球形单细胞淡水绿藻。在脂肪酸合成途径中,脂肪酸去饱和酶与脂肪酸酰基结合载体结合进行脂肪酸去饱和反应。为探究与缺刻缘绿藻中?15脂肪酸去饱和酶（fatty acid desaturase,FAD）结合的脂肪酸酰基结合载体,选用酿酒酵母（Saccharomyces cerevisiae）INVSc1和聚球藻（Synechococcus sp.）PCC7942分别验证?15 FAD与酰基辅酶A（酰基-CoA）或酰基载体蛋白（酰基-ACP）结合的脂肪酸去饱和过程。根据缺刻缘绿藻的?15 FAD基因构建双源表达载体pYES2-?15 FAD和pCAMBIA1300-?15 FAD,通过电穿孔法将重组表达质粒分别转入酿酒酵母INVSc1和聚球藻PCC7942中,筛选得到转基因菌株。取相同细胞数的转基因酵母和转基因聚球藻,培养时分别添加等量的底物亚油酸（linoleic acid,18:2?9,12,LA）,以LA作为酰基受体,使其进入转基因酵母和转基因聚球藻的生物合成途径中,培养36-72 h。利用气相色谱-质谱联用系统对总脂肪酸的各组分进行分析,结果显示,在转基因实验组中检测到LA和?-亚麻酸（?-linolenic acid,18:3?9,12,15 ,ALA）的存在,空白实验则未检测出相应的产物。通过计算,转基因酵母催化LA生成ALA的效率29.31%,转基因聚球藻催化底物LA生成ALA的效率为30.86%。根据结果证明无论是酰基-ACP还是酰基-CoA,与缺刻缘绿藻中的?15 FAD结合进行反应的效率相近,不存在偏好性,由于?15 FAD是特异性蛋白,因此证明缺刻缘绿藻中的?15 FAD属于脂酰基结合蛋白。  相似文献   

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