Folate

叶酸
  • 文章类型: Journal Article
    背景:关于叶酸摄入量和生物标志物与死亡风险之间关系的现有证据存在争议。
    目的:先前的队列研究检查了叶酸摄入量和生物标志物与全因风险的关系,心血管疾病(CVD),和癌症相关死亡率通过系统评价和荟萃分析。
    方法:对PubMed进行了系统搜索,Scopus,和截至2023年7月的ISIWebofScience数据库。
    方法:前瞻性队列研究检查叶酸生物标志物的相关性(血清,等离子体,红细胞)和具有全因风险的摄入,CVD-,并考虑了与癌症相关的死亡率.随机效应模型被应用于结合研究特定的风险估计。通过1阶段加权混合效应荟萃分析评估剂量-反应关系。
    方法:共有25个队列,423304名参与者,36558全因,12662CVT-,纳入2426例癌症相关死亡病例.叶酸生物标志物的最高水平与全因死亡风险之间没有观察到显著关联(风险比[HR],0.91;95%CI,0.77-1.06;n=17;I2=89.4%;P<.001),CVD相关死亡风险(HR,0.97;95%CI,0.87-1.06;n=11;I2=0.0%;P=.57),和癌症相关的死亡风险(HR,0.85;95%CI,0.69-1.05;n=6;I2=57.8%;P=.04)与最低相比。此外,每增加10nmol/L与全因死亡风险降低12%略有相关,但与CVD和癌症相关死亡风险无关.发现膳食叶酸的最高摄入量与最低摄入量之间存在显着负相关,和所有原因的风险(HR,0.87;95%CI,0.78-0.96;n=3;I2=63.6%;P=.06)和CVD(HR,0.77;95%CI,0.57-0.93;n=4;I2=80.2%;P=0.002)死亡率。
    结论:这项荟萃分析显示,膳食叶酸摄入量与全因死亡率和CVD死亡率之间存在显著的负相关关系。在叶酸生物标志物的情况下没有发现这样的关联。需要进一步的前瞻性研究来证实这些发现。
    背景:PROSPERO注册号。CRD42023401700。
    BACKGROUND: Existing evidence on the relation between folate intake and biomarkers with mortality risk is controversial.
    OBJECTIVE: Previous cohort studies were examined regarding folate intake and biomarkers in relation to risk of all-cause, cardiovascular disease- (CVD), and cancer-related mortality through a systematic review and meta-analysis.
    METHODS: A systematic search was performed of the PubMed, Scopus, and ISI Web of Science databases up to July 2023.
    METHODS: Prospective cohort studies examining the association of folate biomarkers (in serum, plasma, red blood cells) and intake with risk of all-cause, CVD-, and cancer-related mortality were considered. A random-effects model was applied to combine study-specific risk estimates. Dose-response relations were assessed by 1-stage weighted mixed-effects meta-analysis.
    METHODS: A total of 25 cohorts with 423 304 participants, 36 558 all-cause, 12 662 CVD-, and 2426 cancer-related deaths were included. No significant association was observed between the highest levels of folate biomarkers and all-cause mortality risk (hazard ratio [HR], 0.91; 95% CI, 0.77-1.06; n = 17; I2 = 89.4%; P < .001), CVD-related mortality risk (HR, 0.97; 95% CI, 0.87-1.06; n = 11; I2 = 0.0%; P = .57), and cancer-related mortality risk (HR, 0.85; 95% CI, 0.69-1.05; n = 6; I2 = 57.8%; P = .04) compared with the lowest. Furthermore, each 10 nmol/L increase was marginally related to a 12% reduced all-cause mortality risk but not to CVD- and cancer-related mortality risk. A significant inverse association was found between highest intake of dietary folate and the lowest, and risk of all-cause (HR, 0.87; 95% CI, 0.78-0.96; n = 3; I2 = 63.6%; P = .06) and CVD (HR, 0.77; 95% CI, 0.57-0.93; n = 4; I2 = 80.2%; P = .002) mortality.
    CONCLUSIONS: This meta-analysis revealed a significant inverse relation between dietary folate intake and risk of all-cause and CVD mortality. Such an association was not found in the case of folate biomarkers. Further prospective studies are warranted to confirm these findings.
    BACKGROUND: PROSPERO registration no. CRD42023401700.
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  • 文章类型: Journal Article
    叶酸是参与嘌呤和嘧啶合成的水溶性B族维生素,是人体生长和生殖必需的维生素之一。叶酸缺乏由于低饮食摄入量,叶酸吸收不良,和改变叶酸代谢由于遗传缺陷或药物相互作用显着增加疾病的风险,如神经管缺陷,心血管疾病,癌症,和认知功能障碍。最近的研究表明,叶酸缺乏可引起高同型半胱氨酸血症,这增加了高血压和心血管疾病的风险,高同型半胱氨酸水平是肝纤维化和肝硬化的独立危险因素。此外,叶酸缺乏导致肝脏中促炎症因子分泌增加和脂质代谢受损,导致肝细胞脂质积累和纤维化。有大量证据表明,叶酸缺乏有助于各种肝脏疾病的发展和进展,包括非酒精性脂肪性肝病(NAFLD),非酒精性脂肪性肝炎(NASH),酒精性肝病(ALD),病毒性肝炎,肝纤维化,还有肝癌.在这里,我们回顾了叶酸在肝脏疾病的病理生理学中的作用的关键研究,总结叶酸治疗肝病的研究现状,并推测叶酸可能是肝脏疾病的潜在治疗靶点。
    Folate is a water-soluble B vitamin involved in the synthesis of purines and pyrimidines and is one of the essential vitamins for human growth and reproduction. Folate deficiency due to low dietary intake, poor absorption of folate, and alterations in folate metabolism due to genetic defects or drug interactions significantly increases the risk of diseases such as neural tube defects, cardiovascular disease, cancer, and cognitive dysfunction. Recent studies have shown that folate deficiency can cause hyperhomocysteinemia, which increases the risk of hypertension and cardiovascular disease, and that high homocysteine levels are an independent risk factor for liver fibrosis and cirrhosis. In addition, folate deficiency results in increased secretion of pro-inflammatory factors and impaired lipid metabolism in the liver, leading to lipid accumulation in hepatocytes and fibrosis. There is substantial evidence that folate deficiency contributes to the development and progression of a variety of liver diseases, including non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), alcoholic liver disease (ALD), viral hepatitis, hepatic fibrosis, and liver cancer. Here we review key studies on the role of folate in the pathophysiology of liver diseases, summarize the current status of studies on folate in the treatment of liver diseases, and speculate that folate may be a potential therapeutic target for liver diseases.
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  • 文章类型: Journal Article
    线粒体一碳代谢为几种途径提供了碳单位,包括核酸合成,线粒体代谢,氨基酸代谢,和甲基化反应。迟发性阿尔茨海默病是最常见的与年龄相关的神经退行性疾病,以能量代谢受损为特征,并可能与线粒体生物能学有关。这里,我们讨论了与线粒体一碳代谢和阿尔茨海默病相关的分子途径之间的交叉。我们认为,增强一碳代谢可以促进代谢过程,帮助脑细胞应对阿尔茨海默病相关损伤。我们还强调了潜在的治疗途径,利用一碳代谢来延缓阿尔茨海默病的病理。
    Mitochondrial one-carbon metabolism provides carbon units to several pathways, including nucleic acid synthesis, mitochondrial metabolism, amino acid metabolism, and methylation reactions. Late-onset Alzheimer\'s disease is the most common age-related neurodegenerative disease, characterised by impaired energy metabolism, and is potentially linked to mitochondrial bioenergetics. Here, we discuss the intersection between the molecular pathways linked to both mitochondrial one-carbon metabolism and Alzheimer\'s disease. We propose that enhancing one-carbon metabolism could promote the metabolic processes that help brain cells cope with Alzheimer\'s disease-related injuries. We also highlight potential therapeutic avenues to leverage one-carbon metabolism to delay Alzheimer\'s disease pathology.
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  • 文章类型: Journal Article
    背景:2023年5月29日,第76届世界卫生大会(WHA)一致通过了题为“,“加快努力预防微量营养素缺乏及其后果,包括脊柱裂和其他神经管缺陷,通过安全有效的食品强化。出生缺陷研究和预防协会于2015年发布了他们的决议,支持用叶酸强制强化主食,并提出了旨在实现全球全面预防叶酸敏感性脊柱裂和无脑畸形的建议。设定到2024年实现的目标。WHA决议为这一事业提供了另一个全球推动力,向成员国提出到2030年实现粮食强化的建议。
    方法:这个简短的交流记录了步骤,从开始到通过,在WHA关于食品强化的第76项决议中,叙述了多个政府和非政府组织的战略宣传工作的性质。
    结果:WHA决议可能需要很多年才能由大会引入和通过;但是,这是一个案例研究,说明强大的全球伙伴关系促成了这一进程的迅速性。
    结论:此过程的文档可作为制定和处理旨在改善全球母婴健康的未来WHA决议的范例。
    BACKGROUND: On May 29, 2023, the 76th World Health Assembly (WHA) unanimously adopted the resolution entitled, \"Accelerating efforts for preventing micronutrient deficiencies and their consequences, including spina bifida and other neural tube defects, through safe and effective food fortification.\" The Society for Birth Defects Research and Prevention published their resolution in 2015 supporting mandatory fortification of staple foods with folic acid and recommendations aiming to achieve global total prevention of folate-sensitive spina bifida and anencephaly, setting a goal to achieve by the year 2024. The WHA resolution provides another global push for the cause, with recommendations to member nations for food fortification to be achieved by the year 2030.
    METHODS: This short communication documents the steps, from inception up to the passage, of the 76th WHA resolution on food fortification, with a narrative on the nature of strategic advocacy efforts by multiple governmental and nongovernmental organizations.
    RESULTS: WHA resolutions can take many years to be introduced and passed by the assembly; however, this is a case study of the swiftness of the process enabled by powerful global partnership.
    CONCLUSIONS: The documentation of this process serves as an example for developing and processing future WHA resolutions aiming to improve global maternal and child health.
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  • 文章类型: Journal Article
    背景:低叶酸摄入量和亚甲基四氢叶酸还原酶(MTHFR)C677T多态性被认为会增加阿尔茨海默病(AD)的风险。然而,协同作用及其对脑结构和灌注的影响尚不清楚.
    方法:本研究探讨了叶酸代谢中的饮食和遗传缺陷对海马亚区体积的影响,脑灌注,71名认知未受损(CU)个体和102名因AD或AD引起的轻度认知障碍(MCI)患者的认知能力下降。所有参与者都接受了磁共振成像,实验室检查,和神经心理学评估。使用Freesurfer分割海马子场,动脉自旋标记用于测量脑血流量。
    结果:我们发现对叶酸存在显著的MTHFR组交互作用效应。与没有这种突变的患者相比,患有AD和677T等位基因的患者在左前肌显示灌注不足,介导了低叶酸水平与携带677CET等位基因患者认知功能下降的关系。此外,在AD患者中,叶酸浓度降低和MTHFR677T等位基因存在对特定海马亚区萎缩的协同作用.
    结论:除了提供对AD中基因依赖性叶酸诱导的认知损害的潜在神经元机制的见解,这些发现对于低叶酸水平且携带MTHFR677T等位基因的AD患者辅助叶酸补充治疗的分配可能具有临床意义,并可能最终促进早期个体化AD药物治疗的选择.
    BACKGROUND: Low folate intake and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism have been suggested to increase the risk of Alzheimer\'s disease (AD). However, the synergistic effects and their impact on brain structure and perfusion remain unclear.
    METHODS: This study explored the effects of dietary and genetic deficiencies in folate metabolism on the volume of the hippocampal subregions, cerebral perfusion, and cognitive decline in 71 cognitively unimpaired (CU) individuals and 102 patients with mild cognitive impairment (MCI) due to AD or AD. All participants underwent magnetic resonance imaging, laboratory examinations, and neuropsychological assessments. The hippocampal subfields were segmented using Freesurfer, and arterial spin labeling was used to measure the cerebral blood flow.
    RESULTS: We found a significant group-by-MTHFR interaction effect on folate. Patients with AD and the 677 T allele showed hypoperfusion in the left precuneus compared to patients without this mutation, which mediated the relationship between low folate level and cognitive decline in patients carrying the 677 T allele. Moreover, a synergistic effect was observed for the combination of decreased folate concentrations and the presence of the MTHFR 677 T allele on the atrophy of specific hippocampal subregions in patients with AD.
    CONCLUSIONS: In addition to offering insights into the neuronal mechanism underlying gene-dependent folate-induced cognitive impairment in AD, these findings may have clinical significance for the allocation of auxiliary folate supplementation therapy in patients with AD with low folate levels and carrying the MTHFR 677 T allele and may eventually promote the selection of early individualized AD drug therapy.
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  • 文章类型: Journal Article
    背景:注意缺陷多动障碍(ADHD)是一种常见的儿童神经发育障碍,始于12岁之前。鉴于B族维生素在细胞代谢中的作用,核苷酸的合成,和神经递质,本研究系统调查了ADHD患儿血浆维生素B9和B12水平。方法:我们搜索了包括WebofScience在内的电子数据库,MEDLINE,EMBASE,Scopus,伊朗MEDEX,Cochran数据库,和SID从概念到2023年6月。全文病例对照或横断面研究纳入本研究。病例组中的参与者是6-12岁的ADHD儿童。使用ReviewManager软件(RevMan5.4)进行统计分析。使用95%CI的标准化平均差异(SMD)来确定两组之间的差异。结果:本荟萃分析包括6项研究。其中包括982名儿童,谁,204人是女孩,744人是男孩。儿童的平均年龄为8.86±2.03岁。有和没有ADHD的儿童之间的维生素B9水平显着不同[SMD-0.80,95%CI(-1.55,-0.04)]。ADHD患儿的维生素B12显著降低[SMD-0.29,95%CI(-0.42,-0.16)]。然而,由于高度异质性(I2=93%),采用敏感性分析,I2降至21%,两组间差异显著[SMD-0.19,95%CI(-0.34,-0.04)]。结论:本次系统评价结果显示,ADHD患儿维生素B9、B12水平明显低于健康儿童。
    Background: Attention deficit hyperactivity disorder (ADHD) is a common childhood neurodevelopmental disorder that begins before age 12. Given the role of B group vitamins in cell metabolism, synthesis of nucleotides, and neurotransmitters, the present study systematically investigated the plasma levels of vitamins B9 and B12 in children with ADHD. Methods: We searched electronic databases including Web of Science, MEDLINE, EMBASE, Scopus, Iran MEDEX, Cochran database, and SID from conception to June 2023. Full-text case-control or cross-sectional studies were included in this study. Participants in the case group were children with ADHD aged 6-12 years. Review Manager Software (RevMan 5.4) was used for statistical analyses. Standardized mean differences (SMD) with 95% CIs were used to determine the differences between the two groups. Results: Six studies were included in the present meta-analysis. They included 982 children, of whom, 204 were girls and 744 were boys. The mean age of the children was 8.86±2.03 years. The level of vitamin B9 was significantly different between children with and without ADHD [SMD -0.80, 95% CI (-1.55, -0.04)]. Vitamin B12 was significantly lower in children with ADHD [SMD -0.29, 95% CI (-0.42, -0.16)]. However, due to high heterogeneity (I2 = 93%), sensitivity analysis was used, I2 fell to 21%, and significant difference was observed between the two groups [SMD -0.19, 95% CI (-0.34, -0.04)]. Conclusion: The results of this systematic review showed that the level of vitamins B9 and B12 in children with ADHD was significantly lower than that in healthy children.
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  • 文章类型: Journal Article
    印度儿童贫血的患病率仍然很高,特别是那些在农村地区,在育龄妇女中,其对神经发育的损害会产生严重的终身影响。令人担忧的是,最新的官方数据(2019-21)表明与2015-16相比,患病率有所上升。在具有社会经济因素的印度各州之间,儿童贫血也存在相当大的差异,例如,财富和教育导致青春期妇女及其子女患贫血的风险。饮食缺铁通常被认为是贫血的主要原因,但从作者正在进行的文献数据库和最近的文献研究中积累的越来越多的证据表明,它具有多因素的病因。其中一些与营养无关。这篇叙述性评论集中在这些多因素问题上,特别是维生素B12/叶酸缺乏的贡献,这在印度也有很高的患病率。还指出,饮食中生物可利用的铁的摄入仍然是减少贫血的重要因素,并简要讨论了与传统主食谷物相比,小米作为改良铁源的作用。总体结论是贫血具有多因素病因,需要多因素评估,必须包括评估维生素B12状态。
    The prevalence of anaemia in India remains high in children, especially those in rural areas, and in women of childbearing age, and its impairment of neurological development can have serious lifelong effects. It is concerning that the most recent official data (2019-21) indicate an increased prevalence compared with 2015-16. There is also considerable variability in childhood anaemia between Indian states with socioeconomic factors, such as wealth and education contributing to the risk of anaemia among adolescent women and their children. Dietary iron deficiency is often regarded as the main contributor to anaemia but increasing evidence accumulated from the authors\' ongoing literature database coupled with recent literature research suggests that it has a multifactorial aetiology, some of which is not related to nutrition. This narrative review focused on these multifactorial issues, notably the contribution of vitamin B12/folate deficiency, which also has a high prevalence in India. It was also noted that the dietary intake of bioavailable iron remains an important contributor for reducing anaemia, and the role of millets as an improved iron source compared to traditional staple cereals is briefly discussed. The overall conclusion is that anaemia has a multifactorial aetiology requiring multifactorial assessment that must include assessment of vitamin B12 status.
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  • 文章类型: Journal Article
    背景:低于或高于医学研究所建议的妊娠体重增加与不良围产期和新生儿结局相关。很少有研究评估血清和红细胞叶酸浓度与青少年妊娠期体重增加之间的关系。此外,怀孕期间锌缺乏与免疫力受损有关,长时间的劳动,早产和早产,宫内生长受限,低出生体重,和妊娠高血压.
    目的:我们研究的目的是评估血清锌浓度之间的关联,血清叶酸,和红细胞叶酸,随着来自墨西哥城的一组青少年母亲的妊娠体重以及新生儿的体重和身长的增加。
    结果:在我们的研究中,406名青春期新生儿参加了比赛。青少年的平均年龄为15.8岁。主要社会经济水平为中低(57.8%),单身(57%),89.9%从事家庭活动,41.3%完成了中学教育。在36.7%的病例中观察到妊娠体重增加过多,而妊娠体重增加不足的占38.4%。在20.9%的样本中观察到小于胎龄的婴儿。低血清叶酸(OR2.1,95%CI1.3-3.3),红细胞叶酸降低(OR1.6,95%CI1.0-2.6),血清锌浓度降低(OR3.3,95%CI2.1-5.2)与妊娠期体重增加不足相关.血清锌水平降低(OR1.2,95%CI1.2-3.4)与分娩胎龄小的婴儿的可能性增加有关。
    结论:低血清叶酸,红细胞叶酸,血清锌浓度与妊娠体重增加和胎龄较小的婴儿有关。妊娠期体重增加过多和不足,以及有一个小胎龄婴儿,在青春期的母亲中很常见。
    BACKGROUND: Gestational weight gain below or above the Institute of Medicine recommendations has been associated with adverse perinatal and neonatal outcomes. Very few studies have evaluated the association between serum and red blood cell folate concentrations and gestational weight gain in adolescents. Additionally, zinc deficiency during pregnancy has been associated with impaired immunity, prolonged labor, preterm and post-term birth, intrauterine growth restriction, low birth weight, and pregnancy-induced hypertension.
    OBJECTIVE: The purpose of our study is to evaluate the association between serum concentrations of zinc, serum folate, and red blood cell folate, with the increase in gestational weight and the weight and length of the newborn in a group of adolescent mothers from Mexico City.
    RESULTS: In our study, 406 adolescent-neonate dyads participated. The adolescents\' median age was 15.8 years old. The predominant socioeconomic level was middle-low (57.8%), single (57%), 89.9% were engaged in home activities, and 41.3% completed secondary education. Excessive gestational weight gain was observed in 36.7% of cases, while insufficient gestational weight gain was noted in 38.4%. Small for gestational age infants were observed in 20.9% of the sample. Low serum folate (OR 2.1, 95% CI 1.3-3.3), decreased red blood cell folate (OR 1.6, 95% CI 1.0-2.6), and reduced serum zinc concentrations (OR 3.3, 95% CI 2.1-5.2) were associated with insufficient gestational weight gain. Decreased serum zinc levels (OR 1.2, 95% CI 1.2-3.4) were linked to an increased probability of delivering a baby who is small for their gestational age.
    CONCLUSIONS: Low serum folate, red blood cell folate, and serum zinc concentrations were associated with gestational weight gain and having a small gestational age baby. Both excessive and insufficient gestational weight gain, as well as having a small gestational age baby, are frequent among adolescent mothers.
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  • 文章类型: Journal Article
    四氢叶酸是参与C1代谢的辅因子,包括腺嘌呤和丝氨酸的生物合成途径。在经典的四氢叶酸生物合成途径中,在许多细菌中,从前体7,8-二氢蝶呤三磷酸(DHNTP)中去除三个磷酸基团的步骤仍不清楚。DHNTP焦磷酸水解酶水解来自DHNTP的焦磷酸并产生7,8-二氢蝶呤单磷酸盐。尽管在肠道细菌乳酸乳球菌和大肠杆菌中已鉴定出两种结构上不同的DHNTP焦磷酸水解酶,其同源物的分布是有限的。这里,我们的目的是在肠道乳酸菌罗伊利摩氏杆菌中鉴定第三个DHNTP焦磷酸水解酶基因。在包括参与二氢叶酸生物合成的基因操纵子中,我们专注于lreu_1276基因,注释为Ham1家族蛋白或XTP/dITP二磷酸水解酶,作为编码DHNTP焦磷酸水解酶的候选者。使用大肠杆菌制备Lreu_1276重组蛋白并纯化。反应产物的生化分析表明,Lreu_1276蛋白对DHNTP表现出显著的焦磷酸水解酶活性。最佳反应温度和pH分别为35°C和约7。在17种测试化合物中,底物特异性相对严格。尽管先前表征的DHNTP焦磷酸水解酶更喜欢Mg2+,Lreu_1276蛋白在Mn2+存在下表现出最大活性,在1mMMn2存在下,比活性为28.2±2.0µmolmin-1mg-1。三种DHNTP焦磷酸水解酶彼此不具有结构相似性。它们的同源物的分布不重叠,这意味着Lreu_1276蛋白代表细菌中第三种结构新颖的DHNTP焦磷酸水解酶。
    目的:罗伊氏乳杆菌中结构新颖的DHNTP焦磷酸水解酶的鉴定为理解具有lreu_1276同源物的细菌中的四氢叶酸生物合成提供了有价值的信息。有趣的是,然而,即使鉴定出DHNTP焦磷酸水解酶的第三个家族,仍然有许多细菌不具有这三个基因中任何一个的同源物,而具有参与蝶呤环结构生物合成的其他基因。这表明细菌中存在未识别的DHNTP焦磷酸水解酶基因。由于人类没有DHNTP焦磷酸水解酶,在四氢叶酸生物合成中负责反应的酶的高度结构多样性可以在设计靶向肠道微生物群中特定细菌组的抑制剂方面提供优势。
    Tetrahydrofolate is a cofactor involved in C1 metabolism including biosynthesis pathways for adenine and serine. In the classical tetrahydrofolate biosynthesis pathway, the steps removing three phosphate groups from the precursor 7,8-dihydroneopterin triphosphate (DHNTP) remain unclear in many bacteria. DHNTP pyrophosphohydrolase hydrolyzes pyrophosphate from DHNTP and produces 7,8-dihydroneopterin monophosphate. Although two structurally distinct DHNTP pyrophosphohydrolases have been identified in the intestinal bacteria Lactococcus lactis and Escherichia coli, the distribution of their homologs is limited. Here, we aimed to identify a third DHNTP pyrophosphohydrolase gene in the intestinal lactic acid bacterium Limosilactobacillus reuteri. In a gene operon including genes involved in dihydrofolate biosynthesis, we focused on the lreu_1276 gene, annotated as Ham1 family protein or XTP/dITP diphosphohydrolase, as a candidate encoding DHNTP pyrophosphohydrolase. The Lreu_1276 recombinant protein was prepared using E. coli and purified. Biochemical analyses of the reaction product revealed that the Lreu_1276 protein displays significant pyrophosphohydrolase activity toward DHNTP. The optimal reaction temperature and pH were 35°C and around 7, respectively. Substrate specificity was relatively strict among 17 tested compounds. Although previously characterized DHNTP pyrophosphohydrolases prefer Mg2+, the Lreu_1276 protein exhibited maximum activity in the presence of Mn2+, with a specific activity of 28.2 ± 2.0 µmol min-1 mg-1 in the presence of 1 mM Mn2+. The three DHNTP pyrophosphohydrolases do not share structural similarity to one another, and the distribution of their homologs does not overlap, implying that the Lreu_1276 protein represents a third structurally novel DHNTP pyrophosphohydrolase in bacteria.
    OBJECTIVE: The identification of a structurally novel DHNTP pyrophosphohydrolase in L. reuteri provides valuable information in understanding tetrahydrofolate biosynthesis in bacteria that possess lreu_1276 homologs. Interestingly, however, even with the identification of a third family of DHNTP pyrophosphohydrolases, there are still a number of bacteria that do not harbor homologs for any of the three genes while possessing other genes involved in the biosynthesis of the pterin ring structure. This suggests the presence of an unrecognized DHNTP pyrophosphohydrolase gene in bacteria. As humans do not harbor DHNTP pyrophosphohydrolase, the high structural diversity of enzymes responsible for a reaction in tetrahydrofolate biosynthesis may provide an advantage in designing inhibitors targeting a specific group of bacteria in the intestinal microbiota.
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  • 文章类型: Journal Article
    叶酸是许多代谢过程的重要组成部分,已知叶酸缺乏会导致各种疾病。叶酸和叶酸,叶酸的合成和化学稳定的形式,丰富的饮食通常用于克服这种缺陷。叶酸和叶酸,易受恶劣环境的影响,使用纳米颗粒富集叶酸是食品工业中深入研究的策略。这篇综述重点介绍了用于开发叶酸/叶酸纳米颗粒的当前方法和基质类型。负载叶酸/叶酸的纳米颗粒可防止肠道吸收过程中和苛刻的食品加工条件下的货物降解,包括,高温,UV光,还有高压灭菌.数据表明,使用蛋白质和生物聚合物的叶酸的纳米强化有效地增强了货物的生物利用度。通过乳液将叶酸包封在生物聚合物中,喷雾干燥和离子凝胶化是简单的方法,可以很容易地扩大在食品工业中的应用。
    Folate is an essential component of many metabolic processes, and folate deficiency is known to cause various disorders. Folate and folic acid, a synthetic and chemically stable form of folate, enriched diet are typically used to overcome this deficiency. Folic acid and folate however, are susceptible to harsh environment and folates enrichment using nanoparticles is an intensively studied strategy in food industry. This review highlights the current methods and types of matrices utilized to develop folic acid/folate carrying nanoparticles. The folic acid/folate loaded nanoparticles prevent cargo degradation during gut absorption and under harsh food processing conditions including, high temperatures, UV light, and autoclaving. The data demonstrates that nanofortifcation of folates using proteins and biopolymers effectively enhances the bioavailability of the cargo. The encapsulation of folic acid in biopolymers by emulsion, spray drying and ionic gelation represent simplistic methods that can be easily scaled up with applications in food industry.
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