金属硫蛋白专利技术研究现状

本文综述了金属硫蛋白的国内专利技术研究现状,指出金属硫蛋白的研究已从其结构和功能研究进入到应用开发研究,应用开发研究涉及生产工艺和产品,研制的生产工艺适合于批量生产锌金属硫蛋白,研制的产品包括含锌金属硫蛋白的保健制剂、金属硫蛋白的饮料以及含金属硫蛋白化妆品。     

金属硫蛋白及其重金属解毒功能研究进展

近年来,全球范围内重金属污染日益严重,大量重金属元素进入人体并产生蓄积,严重威胁到人类健康,因此寻找安全、高效的重金属解毒天然产物引起国内外学者越来越多的重视。金属硫蛋白是一种低分子量、富含半胱氨酸的胞内蛋白质,根据不同的蛋白质结构可将金属硫蛋白分为MT-Ⅰ、MT-Ⅱ、MT-Ⅲ和MT-Ⅳ四种异构形式。金属硫蛋白含有大量巯基,这一特殊结构赋予了其螯合重金属离子及重金属解毒功能。本文综述了目前通用金属硫蛋白定义及其构型分类方式;阐述了不同构型金属硫蛋白的蛋白质结构;重点归纳了金属硫蛋白解除重金属毒性机制及其在重金属解毒产品中的应用。本文同时指出了我国在金属硫蛋白研究与应用方面存在的不足,旨在为金属硫蛋白在重金属解毒方面的研究与应用提供参考依据。     

酵母源金属硫蛋白体外清除自由基及抑菌活性的研究

目的:比较两种异构体形式酵母源金属硫蛋白与动物源金属硫蛋白体外清除自由基及抑菌活性。方法:以VC为对照,分光光度法测定金属硫蛋白对自由基清除率,以金黄色葡萄球菌、大肠杆菌和李斯特氏菌为指示菌,研究金属硫蛋白对致病菌的抑制作用。结果:金属硫蛋白对羟基自由基及DPPH自由基清除能力明显强于VC,但对超氧阴离子自由基的清除效果却低于VC,金属硫蛋白对金黄色葡萄球菌、李斯特氏菌具有一定的抑制作用。金属硫蛋白清除自由基关系为Zn-MT>MT-Ⅰ>MT-Ⅱ。结论:金属硫蛋白具有较强的清除自由基能力,对部分致病菌具有一定的抑制作用,作用效果因金属硫蛋白来源、纯度及构型而不同。     

金属硫蛋白及其在食品工业应用中的研究进展

综述了 3 4篇文献。介绍了金属硫蛋白的结构、理化性质和主要功能 ,并对国内外对金属硫蛋白的研究进展进行了简要介绍 ,说明了金属硫蛋白在食品工业中具有广阔的应用前景。     

新型功能性食品添加剂--金属硫蛋白

金属硫蛋白是一类小分子的金属结合蛋白,随着研究的深入发现它具有多种生物功能,是一种很有前景的新型食品添加剂.本文综述了近年来国内外关于金属硫蛋白的结构、特性和功能的研究进展,并讨论了其在食品方面的应用.     

不同重金属胁迫蔬菜产生金属硫蛋白的同源性检测

目的 对不同重金属胁迫蔬菜产生金属硫蛋白(金属硫组氨酸三甲基内盐)进行同源性检测。方法 用Cd-MT免疫家兔产生IgG后, 用不同浓度硫酸铜、乙酸铅、氯化钴、氯化汞等重金属胁迫萝卜幼苗、油白菜和油麦菜诱导产生金属硫蛋白, 通过免疫印迹检测其同源性。结果 Cd-MT与重金属胁迫三种蔬菜所产生的金属硫蛋白具有同源性; 不同浓度的重金属对幼苗中MTs表达量有影响。结论 Cd-MT诱导家兔产生的IgG可用于农产品中重金属污染的检测。     

氧化·疾病·抗氧化(四十六)

<正>10.5金属硫蛋白金属硫蛋白(metallomionein,MT)是一种富含半胱氨酸金属结合蛋白,平均相对分子质量6,500。得自哺乳动物MT一般含61个氨基酸残基,其中20个为半胱氨酸(CyS),半胱氨酸残基上硫基能结合7个金属离子,通过硫酯键与Cd2+、Zn2+、Cu2+、Hg2+、Ag+等金属离子结合。在哺乳动物、鱼类、某些微生物和植物中广     

含金属硫蛋白鸡蛋水解物对两种乳酸菌体外生长的影响

以乳酸菌生长过程中的pH、OD值和菌落总数为评价指标,研究了普通鸡蛋、含金属硫蛋白鸡蛋、普通鸡蛋水解物以及含金属硫蛋白的鸡蛋水解物对动物双歧杆菌、嗜酸乳杆菌以及两种混合菌的影响。结果表明,鸡蛋水解物作为氮源能够促进乳酸菌的增殖,经比较,最佳氮源为含金属硫蛋白鸡蛋水解物,其动物双歧杆菌、嗜酸乳杆菌和混合菌发酵液OD值为普通鸡蛋水解物的1.05倍、1.08倍和1.09倍。含金属硫蛋白的鸡蛋水解物在动物双歧杆菌、嗜酸乳杆菌以及两种混合菌发酵液的最佳添加量分别为2.0%、1.5%和2.0%,活菌数分别可达7.5×109、3.21×109和2.33×1010 CFU/mL。本研究为开发乳酸菌发酵金属硫蛋白鸡蛋肽产品提供指导。     

锌金属硫蛋白的初步研究

本文介绍了金属硫蛋白的理化性质以及生物学功能。研究了锌诱导家兔肝脏金属硫蛋白产生，提取纯化以及鉴定的方法。     

不同重金属胁迫对小麦金属硫蛋白同源性的影响

用不同浓度的CoCl2、HgCl2、CuSO4、Pb(AC)2处理小麦,研究了重金属胁迫对小麦生长和金属硫蛋白同源性的影响。结果表明:重金属胁迫24h后,小麦叶片即出现伤害症状。不同重金属胁迫小麦产生的金属硫蛋白具有广泛的同源性,对金属硫蛋白的诱导强度也不同。     

Estimation of the dietary intake of pesticide residues, lead, cadmium, arsenic and radionuclides in France

Estimation of the dietary exposure of French consumers to 10 pesticides (omethoate, oxydemeton, phosalon, phosphamidon, triazophos, dicofol (op'+pp'), parathion ethyl, dichlorvos, procymidon and vinchlozolin), three heavy metals (lead, cadmium and arsenic) and three radionuclides (¹³⁴caesium, ¹³⁷caesium and ¹³¹iodine) from collected duplicate portion in mass catering establishments in 1998/1999 are reported, and compared with those from previous French studies as well as those from other countries. Dietary exposure estimates appear to be reassuring, in that Estimated Daily Intake (EDI) estimates are generally low, representing at maximum only 4% of the Acceptable Daily Intake (ADI) for pesticide residues and 28% of the Provisional Tolerable Weekly Intake (PTWI) for heavy metals. Moreover, none of the three radionuclides has been found in duplicate meals. When comparisons are possible, estimated dietary exposures for heavy metals are lower than those from previous French studies and similar or above those from other countries.     

稻谷重金属检测和去除方法的研究进展

现代工业快速发展导致部分稻谷污染了一定程度的重金属,解决稻谷重金属污染问题是保障粮食安全的重要内容。本文基于国内外的研究现状,首先总结比较了重金属检测方法的优缺点,其次总结了重金属在稻谷中的分布及存在形态,最后重点综述了对稻谷加工各个环节产物采取的重金属去除方法,展望了今后的研究方向,为重金属污染稻谷的合理利用提供借鉴。     

Heavy metal capture and accumulation in bioretention media

Heavy metal capture and accumulation in bioretention media were investigated through the use of a one-dimensional filtration equation for particulate metals, advection/dispersion/adsorption transport equations for dissolved metals, and sequential extractions. Predicted spatial profiles and partitioning patterns of captured metals were compared to data derived from a bioretention cell in the District of Columbia. Zinc, lead, and copper profiles showed a high surface accumulation, significantly decreasing with the media depth. Surface street particle-enriched areas had the highest heavy metal levels, demonstrating a close relationship between capture of metals and runoff particles. Sequential extractions suggested that most captured metals were of anthropogenic origin. Soluble-exchangeable bound metals from the sequential extraction correlated well with predicted aqueous dissolved metals; the more strongly associated metal fractions correlated with modeled runoff and media particulate metals. A simple risk evaluation indicated thatlead isthe limiting metal in bioretention accumulation. On the basis of information collected in this study, a shallow bioretention cell design is suggested for systems with a focus on metal capture.     

水产品中重金属生物可给性与生物有效性研究进展

水产品对重金属具有富集作用,因此时常出现的重金属含量超标现象成为影响水产品质量安全的重要因素,在降低消费者信心的同时也严重影响了整个水产行业经济的健康发展.重金属对人体产生的毒副作用跟其摄入体内被吸收利用的程度相关,只有被肠道吸收的部分才会对人体产生危害.因此,为了更加科学地评估食品中重金属等有毒有害物质的危害,可通过...     

金属材料高频电磁波响应研究

不同频率的电磁波在金属材料中,有着不同的导电极限频率。各种金属材料都有各自的高频极限,高频极限是区分材料作为导电体与电介质的分界线。通过建立理想化的金属晶格模型,导出了金属材料的高频极限关系式,从而明确了电介质材料与金属材料的高频频率分界,对于研究电磁波与金属材料的作用机理有着实际意义。     

食品中重金属检测与脱除技术研究进展

由于重金属在人体内的累积效应会产生潜在的健康危害,使得食品中的重金属脱除与检测技术越来越受到国内外学者的重视。文章对食品中重金属检测方法的原理及特点进行综述,并介绍几种主要的重金属脱除技术(浸泡法、化学法、吸附法、离子交换法等),同时对食品中重金属脱除技术的未来发展进行展望。     

2020年北京市售食用菌中重金属含量及健康风险分析

目的 检测北京市售食用菌中重金属含量并进行健康风险评测。方法 采用随机采样的方法,选取北京市售常见新鲜食用菌,采用电感耦合等离子体质谱对食用菌中重金属砷、镉、铅、汞含量进行检测;采用靶标危害系数法 (target hazard quotients, THQ),评估人体每日通过食用菌摄入重金属所带来的健康风险。结果 共采集食用菌样品5类42份,重金属砷、镉、铅、汞含量均未超过国标限量要求,其中香菇中各种重金属的含量相对较高,各种重金属在不同种类食用菌中含量差异变化较大;儿童、成人摄入食用菌中重金属的THQ值和总THQ值依次递减。不同年龄人群膳食摄入食用菌中砷、镉、铅、汞的THQ值均＜1。结论 本次采集的北京市售食用菌中砷、镉、铅、汞的含量均未超标,通过膳食途径摄入食用菌中重金属的健康风险较低。     

崇明区食用农产品重金属污染状况及健康风险评估

目的了解上海市崇明区食用农产品中铅、砷、汞、镉等重金属的污染状况及其对人体健康风险评估。方法对全区290件食用农产品中的铅、砷、汞、镉等重金属进行监测,利用单因子污染指数法以及综合污染指数法分析重金属污染特征,采用健康风险分析法评价农产品中重金属对人体的健康风险。结果 290件样品中的4种重金属均未超出标准限量值,水果中重金属污染水平均低于0.6,属于清洁水平;蔬菜和稻谷中重金属污染物残留较多,属于尚清洁水平。谷物和蔬菜中重金属危害系数均小于1。结论崇明区食用农产品中重金属存在一定的污染残留,靶标危害系数法分析结果表明未对人体造成健康风险。     

Occurrence of trace metals in foodstuffs and their health impact

BackgroundUnlike organic pollutants, heavy metals are not created nor are biodegradable materials. They naturally occur in earth crust and many of them reach the environment via anthropogenic activities, which belonged to mining, smelting, production of fertilizers, pesticide applications and others.Scope and approachDue to their water solubility and bioaccumulative tendency in different matrices of the environment, some heavy metals are extremely toxic even at low exposure levels and can be transported into the food chain.Key findings and conclusionsMany criteria are defined to identify heavy metals based on their specific gravity, weight and atomic number, chemical properties and their toxicity, therefore the heavy metals term is still very loose. Dietary exposure is a significant route for trace metals to the humans and constitutes about 90% of exposure. Long term exposure to metals via food consumption, drinking water or other occupational sources leads to serious problems, e.g., hepatotoxicity, kidney failure and neurotoxicity. Analysis of the current situation concluded that the concentrations of heavy metals declined over the years, but they are still hot spots suffering from domestic wastes, agrochemicals like pesticides, fertilizers and industrial wastes. Due to the contamination sources in those hot spots, levels of some metals exceeded the approved permissible limits and become sources of severe problems to humans. Almost comprehensive hazard assessment of these metals is missing due to insufficient data corresponding to body burden for groups potentially exposed to high concentration of metals and their concentrations in foodstuffs.     

Metals in commonly eaten groceries in Western Australia: a market basket survey and dietary assessment

Children’s dietary exposure to metals has received limited attention in Australia. This study undertook a market basket survey and analysed 253 food and beverages for metals. These data were used in conjunction with recent average diet data for children in Western Australia to model dietary metals exposure, with mean metals intakes calculated for boys and girls aged 8, 12, 13 and 16 years. Results show that for some metals, including cadmium, nickel and manganese, dietary intake guidelines have been exceeded in younger children. The mean modelled cadmium intake in children aged 8 years was almost 60% of the World Health Organisation (WHO) guideline and exceeded the European Food Safety Authority (EFSA) guideline. Nickel and manganese intake was higher in younger children than reported in international studies. Modelling based on the 95% percentile of dietary consumption exceeded the respective guidelines or upper level of intake for several of the metals studied. The findings from this study support the need for further investigation into the exposure of children to metals from diet and the health implications of exposure.