纳豆激酶纤溶活性研究

通过制备纳豆提取液、纳豆激酶粗酶,对纳豆激酶纤溶活性进行研究。结果表明:纳豆激酶纤溶活性最适pH为8.0,pH6~10溶液中40℃以下基本稳定,pH<5失去纤溶活性;模拟胃环境的酸性条件下,粗酶失去纤溶活性,而纳豆浸提液纤溶活性保持25%;SDS-PAGE电泳显示,胰蛋白酶对纳豆激酶成分没有降解作用;体外溶栓作用表明,纳豆激酶溶解纤维蛋白的方式是直接溶解,而不是通过激活纤溶酶原。     

纳豆激酶的研究进展

纳豆激酶有很强的溶血栓能力,跟传统的一些溶栓剂相比,具有安全性好、成本低、口服有效等优点,极有可能开发为新一代的溶栓剂。介绍了纳豆激酶的分离纯化技术、生化特性,并对纳豆激酶的活性测定方法、影响纳豆激酶稳定性的因素及提高纳豆激酶酶产量的几种途径等最新研究成果进行了综述。     

纳豆激酶的研究进展

纳豆激酶有很强的溶血栓能力,跟传统的一些溶栓剂相比,具有安全性好、成本低、口服有效等优点,极有可能开发为新一代的溶栓剂。本文介绍了纳豆激酶的分离纯化技术、生化特性;并对纳亚激酶的活性测定方法、影响纳豆激酶稳定性的因素及提高纳豆激酶酶产量的几种途径等最新研究成果进行了综述。     

纳豆激酶的研究进展

纳豆激酶有很强的溶血栓能力，跟传统的一些溶栓剂相比，具有安全性好、成本低、口服有效等优点，极有可能开发为新一代的溶栓剂。本文介绍了纳豆激酶的分离纯化技术、生化特性；并对纳豆激酶的活性测定方法、影响纳豆激酶稳定性的因素及提高纳豆激酶酶产量的几种途径等最新研究成果进行了综述。     

大豆激酶的开发与应用

大豆激酶亦称纳豆激酶，是一种能溶解和阻滞造成人体血管栓塞的纤维蛋白，具有通检作用的酶制剂。1大豆激酶的物性特点提纯的纳豆激酶为白色、无臭的粉末，该激酶是一种蛋白质。氨基酶的排列顺序已弄清，是由含丙氨酸的275个残基组成，其分子量为2O000，是一条单链多肽，它比尿激酶和组织性纤溶酶原激活物和纤溶酶分子量小得多。它不仅能静脉注入，而且口服效果也非常良好，使用亦很方便。2药理作用纳豆激酶不仅能直接有溶解血栓的作用，而且还能引起人体内组织性纤溶酶原激活物的增加和激活人体内的尿激酶原，起到双重的溶栓作用。纳豆檄…     

纳豆激酶的研究进展

纳豆激酶是由纳豆芽孢杆菌 (Bacillusnatto)分泌的一种具有强烈纤溶作用的丝氨酸蛋白酶。文章中对纳豆菌产生的纳豆激酶的分离纯化、基因结构、蛋白质结构、生物学功能及其在医疗上的溶纤特性进行了综述     

紫外分光光度法测定纳豆激酶体外纤溶活力

建立短时间、定量测定纳豆激酶体外纤溶活力的方法。在体外反应体系中制备血纤维蛋白底物,向体系中加入待测样品(纳豆激酶),进行纤溶反应。用紫外分光光度计测定纳豆激酶水解纤维蛋白后生成的可溶性产物的吸光值。由此对纳豆激酶体外纤溶活性进行定量测定并进行方法可行性分析。该方法具有较好的灵敏度、精密度和准确度,用时短,该方法适用于纳豆激酶体外纤溶活性的定量分析。     

纳豆激酶的研究进展

纳豆激酶有很强的溶血栓能力，跟传统的一些溶栓剂相比，具有安全性好，成本低，口服有效等优点，极有可能开发为新一代的溶栓剂。本文介绍了纳豆激酶的分离纯化技术，生化特性；并对纳豆激酶的活性测定方法，影响纳豆激酶稳定性的因素及提高纳豆激酶酶产量的几种途径等最新研究成果进行了综述。     

纳豆激酶的研究现状与展望

纳豆激酶是从日本传统食品纳豆中提取的一种枯草杆菌蛋白酶,具有高效的抗血栓作用,而且易吸收,无副作用,有望被开发为新一代的口服抗血栓药物。本文概括了纳豆激酶的基本生化性质,溶血栓作用及机理,介绍了其酶活测定方法和分离纯化方法,并对纳豆激酶的开发应用进行了展望。     

纳豆激酶的纯化及性质研究

从固态发酵培养的纳豆中提取纳豆激酶 ,采用盐析、疏水层析、离子交换层析等方法 ,对提取液进行纳豆激酶的分离纯化。经SDS 聚丙烯酰胺凝胶电泳鉴定 ,活性酶蛋白为单一组分 ,并测得其分子质量为 2 8ku。纳豆激酶在pH5 0～ 1 0 0 ,4～ 3 7℃范围内具有较好的稳定性 ,其纤溶活性可被 0 1mmol/L的PMSF完全抑制。体外溶栓实验表明 ,纳豆激酶为纤溶酶而不是纤溶酶原激活剂。     

纳豆激酶分子结构与潜在应用价值分析

纳豆激酶因具有较强的溶血能力而著称。目前国内外大量研究人员聚焦于纳豆激酶研究,其开发利用已经获得了长足发展,但同时许多问题与不足也随之暴露出来。一方面是对纳豆激酶的开发利用大多局限于溶栓活性的利用与开发,低估了纳豆激酶应有的整体价值;其次是针对该酶开发和利用的方法过于传统,尚未形成组学大数据和生物信息学技术相结合的探索思维。因此,需要利用更为开阔的研究思路和开发手段来实现纳豆激酶开发利用的最大化。作者从纳豆激酶分子水平和家族分类层次上系统地阐述该酶分子特征,同时对纳豆激酶家族蛋白酶的应用现状进行分析,并对纳豆激酶研发前景进行了展望。     

Inhibitory effect of oral administration of Sangwhang mushroom (Phellinus linteus) grown on germinated brown rice on experimental lung metastasis and tumor growth in mice

Here, the effect of oral administration of the extract of sangwhang mushroom (Phellinus linteus, PL) grown on germinated brown rice on lung metastasis of tumor cells was examined in mice, and a possible immunological action was suggested. Oral administration of the extract of sangwhang mushroom grown on germinated brown rice (PB, 90 mg/kg) prior to tumor inoculation significantly inhibited experimental lung metastasis produced by colon 26-M3.1 carcinoma cells. Also oral administration of PB after tumor inoculation significantly inhibited experimental lung metastasis of tumor cells. In addition, oral administration of PB significantly suppressed tumor growth as well as tumor-induced angiogenesis. However, neither PL nor germinated brown rice (BR) was active. Oral administration of PB, but not PL and BR, resulted in a significant enhancement of natural killer (NK)-mediated killing activity against tumor cells. These results suggest that oral administration of PB can induce antitumor activity to inhibit tumor metastasis, and its antitumor effect is associated with NK cell activation.     

豆豉溶栓酶的研究新进展

豆豉溶栓酶是豆豉中的某些微生物在发酵过程中产生的一种碱性丝氨酸蛋白酶.跟传统的一些溶栓药物相比,它不仅具有很强的溶血栓能力,还具有安全性好、成本低、口服有效等优点,极有可能开发为新一代的溶栓剂.论文重点对金属离子以及酶抑制剂对豆豉溶栓酶的理化性质影响、豆豉溶栓酶高产菌种选育方法、溶栓酶生物活性及酶制荆产品开发等最新研究成果进行了综述.为深入研究豆豉溶栓酶的特性,进一步开发豆豉溶栓酶产品提供了科学研究基础.     

纳豆激酶的研究进展与展望

纳豆激酶主要是由枯草芽孢杆菌（Bacillus subtilis）代谢产生的碱性丝氨酸蛋白酶,因其具有较强的溶栓能力而著称。与其他的大多溶栓剂相比,纳豆激酶具有安全性好、成本低、易吸收、副作用小等优点,因此可用于开发溶栓药物。该文对国内外纳豆激酶的溶栓功效、理化特性、发酵工艺、活性测定、纯化、改性和产品进行了综述,对其当前研究中的关键问题进行分析,并对未来纳豆激酶的研究方向进行了展望。     

Screening of a Bacillus subtilis strain producing both nattokinase and milk-clotting enzyme and its application in fermented milk with thrombolytic activity

Bacillus subtilis is a generally recognized as safe probiotic, which is used as a starter for natto fermentation. Natto is a functional food with antithrombus function due to nattokinase. Compared with natto, fermented milk is a more popular fermented food, which is commonly fermented by Lactobacillus bulgaricus and Streptococcus. However, there is no report on B. subtilis–fermented milk. In this study, to produce a functional fermented milk with antithrombus function, a B. subtilis strain (B. subtilis JNFE0126) that produced both nattokinase and milk-clotting enzyme was isolated from traditionally fermented natto and used as the starter for the functional fermented milk. In liquid fermentation culture, the peak values of thrombolytic activity and milk-clotting activity were 3,511 U/mL at 96 h and 874.5 Soxhlet unit/mL at 60 h, respectively. The optimal pH and temperature were pH 7.0 at 40°C for nattokinase and pH 6.5 and 55°C for milk-clotting enzyme, respectively. The thrombolytic activity in the fermented milk reached 215.1 U/mL after 8 h of fermentation. Sensory evaluation showed that the acceptance of the milk fermented by B. subtilis JNFE0126 was similar to the traditional milk fermented by L. bulgaricus and S. thermophilus. More importantly, oral intake of the fermented milk by the thrombosis-model mice prevented the development of thrombosis. Our results suggest that B. subtilis JNFE0126–fermented milk has potential as a novel, functional food in the prevention of thrombosis-related cardiovascular diseases.     

Preventive effects of edible mushroom (Hypsizigus marmoreus) on mouse type IV allergy: fluctuations of cytokine levels and antioxidant activities in mouse sera

ABSTRACT:  We investigated the mechanisms for the antiallergic effects of Hypsizigus marmoreus mushrooms on an oxazolone-induced type IV allergy in male ICR mice. Serum levels of interleukin-12 (IL-12) and γ-interferon (γ-IFN) were significantly increased in mice, which showed a severe ear edema induced by the type IV allergy in comparison with those of normal mice. The oral administration of an ethanol extract of H. marmoreus for 3 d at a dose of 250 mg/kg body weight prevented the increase of serum IL-12 levels but not γ-IFN levels. Lowering of serum levels of interleukin-2 (IL-2), spleen natural killer (NK) cell activity, and serum antioxidant activity in mice with allergic symptoms were also prevented by oral administration of the ethanol extract. These results suggested that one of the antiallergic mechanisms of H. marmoreus would be due to maintenance of antioxidant status and inhibition of the fluctuations of cytokines in allergic mice.     

Pregnancy-induced changes in substance P and neurokinin 1 receptor (NK1-R) expression in the rat uterus

Adrenergic nerve fibres of the mammalian uterus degenerate during pregnancy. The behaviour of peptidergic fibres, such as substance P-positive fibres and of its preferred neurokinin 1 receptor (NK1-R), is poorly studied in the pregnant rat uterus. The present study analysed the changes in substance P immunoreactivity and in the expression of NK1-R protein in the uterus of non-pregnant, pregnant (days 7, 14 and 21) and postpartum rats (days 1, 8 and 22) by immunohistology, dot blot analysis and western blot analysis. In non-pregnant rats, substance P-positive fibres were localized to the myometrium; these fibres progressively disappeared during gestation and were almost absent at term (day 21). At day 22 post partum, substance P-positive fibres had recovered to numbers comparable with those in the non-pregnant uterus. Dot blot analysis revealed a significant decrease in the immunoreactivity of substance P in the uterus at mid-pregnancy (day 14) and especially at term. Expression of the NK1-R protein showed a progressive increase throughout pregnancy reaching a peak on day 1 post partum; downregulation of NK1-R protein occurred on day 8 post partum. The low and high expressions of NK1-R protein were coincident with a large number of eosinophils and almost no eosinophils in the uterus at oestrus and at term, respectively. It was concluded that substance P immunoreactivity is inversely correlated with NK1-R protein expression in the pregnant and postpartum uterus. The marked upregulation of NK1-R protein at term and after birth indicates that the NK1-R may be involved in the complex regulation of labour and postpartum physiology. However, it is likely that the NK1-protein is not involved in the recruitment of eosinophils into the uterus at oestrus.     

番茄红素的安全性评价及对小鼠免疫功能的影响

目的：研究番茄红素的食品安全性及对小鼠免疫功能的影响。方法：进行大鼠30 d喂养实验,小鼠急性毒性实验,测定小鼠细胞免疫功能、体液免疫功能、单核-巨噬细胞功能及NK细胞活性。结果：雌、雄小鼠的番茄红素急性经口毒性＞2 666.64 mg/kg,属实际无毒级;番茄红素200、433.33、666.67 mg/（kg•d）剂量（以体质量计,下同）在30 d喂养实验中没有对大鼠的血液常规和血清生化指标产生影响,且Ames实验、小鼠骨髓细胞微核实验、小鼠精子畸形实验结果呈阴性;以33.33、66.67、200 mg/（kg•d）3 个剂量进行小鼠免疫功能实验,200 mg/（kg•d）剂量组的鸡红细胞吞噬指数、自然杀伤（natural killer,NK）细胞活性高于阴性对照组,且差异均有统计学意义（P＜0.05）。结论：番茄红素食品安全性良好,高剂量番茄红素作为食品添加剂在小型啮齿类动物实验中具有增强免疫力的功能。     

金属离子对纳豆激酶的化学修饰研究

纳豆激酶(Nattokinase,简称NK)是一种新型食源性纤溶酶,具有很强的溶血栓作用。本项研究采用金属离子对纳豆激酶进行置换修饰研究,找出最佳金属离子的种类和浓度,提高酶活性,以更大的发挥其药理学功能。实验结果表明,修饰后纳豆激酶的酶活性及稳定性有明显的提高,6mmol/L的Mg2+对酶有明显的激活作用,比天然酶提高了45%的活性。Ca2+、Mn2+、Ni2+则表现出不同程度的抑制作用。因此,可通过加入Mg2+来改善提高纳豆激酶的活性。     

纳米级再生型复合抗菌整理剂QP-NK的制备研究

将天然抗菌剂、有机抗菌剂以及纳米无机抗菌剂有效复合,制备出了具有适度抗菌作用的纳米再生型复合抗菌整理剂QP-NK,并采用粒度分析仪、透射电镜、沉降法等对QP-NK的性能进行了表征,对QP-NK整理后的羊毛织物抗菌性进行了检测,在扫描电镜下观察了整理后织物的表面形态.结果表明:复合抗菌剂QP-NK具有较好的分散稳定性,放置1个月无明显分层或沉降现象,其中无机粒子呈纳米级分布.利用该抗菌剂整理后的羊毛织物抑菌率为86.87%,经50次家庭洗涤,抑菌率为77.50%,抑菌保持率达90%以上,满足了适度性、持久性抗菌的要求,而且对织物色泽和手感没有明显影响.