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本文合成了一种聚脯氨酸亲和层析凝胶,并用这种凝胶纯化了猪血小板外廓蛋白。纯化的外廓蛋白在SDS-聚丙烯酰胺凝胶电泳中呈单一蛋白带,分子量14kD;在体外能显著抑制肌动蛋白聚合。 相似文献
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蓖麻蚕卵天冬氨酸蛋白酶纯化及性质 总被引:2,自引:0,他引:2
采用硫酸铵沉淀,离子交换层析和离子交换凝胶过滤法,从蓖麻蚕卵母细胞中纯化出一种蛋白酸疼。该蛋白酶活性能被天冬氨酸蛋白酶特性异性抑制剂胃肽抑制,初步鉴定该酶为天冬氨酸蛋白酶,经SDS-聚丙烯配角安凝胶电泳测得电泳测得分子量为90kD,由凝胶过滤估计分子量在360kD,推测该酶由四亚基组成。 相似文献
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白及块茎铜,锌超氧物歧化酶的纯化及其性质 总被引:1,自引:0,他引:1
白及(Bleillastriata(Thunb.)Reichb.f.)的SOD同工酶只有一条较宽的谱带,确认为Cu·Zn-SOD。其块茎SOD总活性和比活性都高,且含有丰富的白及胶;经丙酮分级沉淀,SephadexG100凝胶过滤和DEAE-纤维素柱层析分离纯化,获得对CN ̄-敏感的淡兰色Cu·ZnSoD粉末。在凝胶电泳染色图谱上,纯化后的酶与粗酶液的SOD区带相对应,且其酶活性染色带与蛋白染色带位置对应,表明已纯化到均一程度。该酶分子量约33KD,亚基分子量约为16.4KD;紫外光区的吸收峰在264.6nm,等电聚焦电泳呈现一条蛋白区带,pH值在4.35左右;该酶在pH6.0~10.0,温度在50℃范围内具稳定性。纯化后的酶为4563.2u/mg·蛋白,纯化了51倍,活力回收为22.3%。上述酶没有过氧化氢酶活性。提取过程中还得到高质量的副产品白及胶。 相似文献
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圆弧青霉碱性脂肪酶的分离纯化的特性 总被引:1,自引:0,他引:1
圆弧青霉突变株PG37发酵液经离心、硫酸铵盐析、疏水层析、阴离子交换层析和凝胶过滤分离纯化得到了比活性为每毫克蛋白质5200u的碱性脂肪酶,纯化倍数16.5,得率33.2%,在聚丙烯酰胺凝胶电泳(PAGE)和SDS-聚丙烯酰胺凝胶电脉(SDS-PAGE)上均呈现单一 白质条带。SDS-PAGE和凝胶过滤分别测得酶的分子量为27.5kD和29.kD,表明该酶以单体形式存在。N末端10个氨基酸的序列测 相似文献
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猪肝微粒体NADH—细胞色素b5还原酶的纯化及特性分析 总被引:2,自引:0,他引:2
采用硫酸铵分级分离,Sephadex G-100凝胶过滤,DEAE-纤维素离子交换层析以及5'-AMP-Sepharose 4B亲和层析,从猪肝微粒体中纯化得到可溶性的NADH-细胞色素b5还原酶,提纯倍数为750-800。总回收率为40%左右。纯化的酶呈典型的黄素蛋白吸收光谱,A273/A460比值为5.8.在SDS-聚丙烯酰胺凝胶电泳板上呈单一的蛋白质区带,分子量为32kd。NADH和2,6- 相似文献
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为纯化和鉴定感觉神经特异蛋白,以兔脊髓背根神经节及背根纤维组织为材料,通过制备匀浆、离子交换层析 D E A E Sephacel,高压液相凝胶过滤层析分离纯化了脊神经感觉神经元 35 k D蛋白,将其作为抗原制备抗 35 k D 多克隆抗体. W estern blot 的结果表明,该蛋白特异地存在于脊感觉神经而不存在于脊运动神经.并初步观察到它对鸡胚背根节有神经营养作用. 相似文献
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Meylomonas sp.GYJ3菌的甲烷单加氧酶(MMO)粗酶提取液经DEAE-Sepharose CL-6B阴离子交换层析,Sephadex G-100凝胶过滤层析和DEAE-TSKgel HPLC分离纯化出MMO还原酶组分,经HPLC分析,纯度大于95%,纯化倍数为4.4,加入至MMO羟基化酶和调节蛋白B的体系中表现比活为228nmol环氧丙烷每分钟毫克蛋白,SDS-PAGE电泳表明的酶由 相似文献
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The ultrastructure and systematics of two red colored freshwater cryptomonads, Storeatula rhinosa , sp. nov. and Pyrenomonas ovalis , sp. nov., are described for the first time. Storeatula, which had been described from marine waters only, has a single inner periplast sheet and a fibrous surface periplast component. Cells lack a furrow but possess a gullet, a bilobed chloroplast connected by a pyrenoid and a nucleomorph located in an indentation of the pyrenoid. This freshwater Storeatula possesses the same general features as the marine species, but it has a contractile vacuole and lacks the lobed chloroplast of S. major. P. ovalis has the generic characteristics described for marine species of Rhodomonas. These characteristics include a short furrow, a deep gullet, square inner periplast plates with beveled corners, a slightly fibrillar surface periplast component, a single chloroplast with two lobes connected by a pyrenoidal bridge and a nucleomorph located in an indentation of the pyrenoid. 相似文献
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Wnt proteins and Wnt signalings have been implicated in a variety of development and cell processes, while aberrant activation of Wnt signaling is linked to a range of cancers in many tissues. In this study, we used the HEK293 cell line to investigate the effects of Wnt3a and Wnt5a on proliferation and apoptosis in a serum starvation culture. After Wnt3a and Wnt5a proteins were expressed, they both promoted the proliferation of HEK293 cells under serum starvation. After 48h of serum starvation, both Wnt3a and Wnt5a inhibited serum starvation-induced apoptosis of HEK293 cells and continued up to 96h. We demonstrated that Wnt3a and Wnt5a can promote proliferation of HEK293 cells and inhibit serum starvation-induced apoptosis, which implies that Wnt3a and Wnt5a can maintain the survival of HEK293 cells under stress, and also provide a novel insight into the role of Wnt3a and Wnt5a and their related signalings in carcinogenesis. 相似文献
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The ribosomal protein S27a (RPS27a) is cleaved from the fusion protein ubiquitin–RPS27a (Ub–RPS27a). Generally, Ub and RPS27a are coexpressed as a fusion protein but function independently after Ub is cleaved from RPS27a by a deubiquitinating enzyme. As an RP, RPS27a assembles into ribosomes, but it also functions independently of ribosomes. RPS27a is involved in the development and poor prognosis of various cancers, such as colorectal cancer, liver cancer, chronic myeloid leukemia, and renal carcinoma, and is associated with poor prognosis. Notably, the murine double minute 2/P53 axis is a major pathway through which RPS27a regulates cancer development. Moreover, RPS27a maintains sperm motility, regulates winged aphid indirect flight muscle degeneration, and facilitates plant growth. Additionally, RPS27a is a metalloprotein and mercury (Hg) biomarker. In the present review, we described the origin, structure, and biological functions of RPS27a. 相似文献
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Purification of proteins is commonly a multiple-step process involving size exclusion, ion exchange, affinity, hydrophobic, and other modes of chromatography. In an effort to circumvent the laborious process of collecting the solutes from each column and reintroducing them onto a second column, a valving system is described that directs the samples eluted from a high-performance liquid chromatographic column through a detector with a high-pressure cell into either a second column or into storage loops of a multiloop value. This multiloop value is referred to as a high-pressure fraction collector. After development of the first column is complete, a second solvent can be directed to the second column or high-pressure fraction collector to elute the solutes back through the detector and onto any other column in the system. The process of eluting a sample from a column through a single detector and directing it to the high-pressure fraction collector or any other column in the system may be repeated a number of times. Such valving systems make it possible to chromatograph a single protein component on two or three columns in a short time. 相似文献
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Lamon-Fava S Marcovina SM Albers JJ Kennedy H Deluca C White CC Cupples LA McNamara JR Seman LJ Bongard V Schaefer EJ 《Journal of lipid research》2011,52(6):1181-1187
The aim of this study was to assess the independent contributions of plasma levels of lipoprotein(a) (Lp(a)), Lp(a) cholesterol, and of apo(a) isoform size to prospective coronary heart disease (CHD) risk. Plasma Lp(a) and Lp(a) cholesterol levels, and apo(a) isoform size were measured at examination cycle 5 in subjects participating in the Framingham Offspring Study who were free of CHD. After a mean follow-up of 12.3 years, 98 men and 47 women developed new CHD events. In multivariate analysis, the hazard ratio of CHD was approximately two-fold greater in men in the upper tertile of plasma Lp(a) levels, relative to those in the bottom tertile (P < 0.002). The apo(a) isoform size contributed only modestly to the association between Lp(a) and CHD and was not an independent predictor of CHD. In multivariate analysis, Lp(a) cholesterol was not significantly associated with CHD risk in men. In women, no association between Lp(a) and CHD risk was observed. Elevated plasma Lp(a) levels are a significant and independent predictor of CHD risk in men. The assessment of apo(a) isoform size in this cohort does not add significant information about CHD risk. In addition, the cholesterol content in Lp(a) is not a significant predictor of CHD risk. 相似文献
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Musculoskeletal models are made to reflect the capacities of the human body in general, and often a specific subject in particular. It remains challenging to both model the musculoskeletal system and then fit the modelled muscles to a specific human subject. We present a reduced muscle model, a planar musculoskeletal model, and a fitting method that can be used to find a feasible set of active and passive muscle parameters for a specific subject. At a minimum, the fitting method requires inverse dynamics data of the subject, a scalar estimate of the peak activation reached during the movement, and a plausible initial estimate for the strength and flexibility of that subject. While additional data can be used to result in a more accurate fit, this data is not required for the method solve for a feasible fit. The minimal input requirements of the proposed fitting method make it well suited for subjects who cannot undergo a maximum voluntary contraction trial, or for whom recording electromyographic data is not possible. To evaluate the model and fitting method we adjust the musculoskeletal model so that it can perform an experimentally recorded stoop-lift of a 15 kg box. 相似文献
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Elisa Cannizzo Aliyah R. Sohani Judith A. Ferry Ephraim P. Hochberg Michael J. Kluk Michelle E. Dorn Craig Sadowski Janessa J. Bucci Adam M. Ackerman Janina A. Longtine Giovanni Carulli Frederic I. Preffer 《Journal of Hematopathology》2009,2(3):163-170
Multiple malignancies may occur in the same patient, and a few reports describe cases with multiple hematologic and non-hematologic neoplasms. We report the case of a patient who showed the sequential occurrence of four different lymphoid neoplasms together with a squamous cell carcinoma of the lung. A 62-year-old man with adenopathy was admitted to the hospital, and lymph node biopsy was positive for low-grade follicular lymphoma. He achieved a partial remission with chemotherapy. Two years later, a PET-CT scan showed a left hilar mass in the lung; biopsy showed a squamous cell carcinoma. Simultaneously, he was diagnosed with diffuse large B cell lymphoma in a neck lymph node; after chemo- and radiotherapy, he achieved a complete response. A restaging PET-CT scan 2 years later revealed a retroperitoneal nodule, and biopsy again showed a low-grade follicular lymphoma, while a biopsy of a cutaneous scalp lesion showed a CD30-positive peripheral T cell lymphoma. After some months, a liver biopsy and a right cervical lymph node biopsy showed a CD30-positive peripheral T cell lymphoma consistent with anaplastic lymphoma kinase-negative anaplastic large cell lymphoma. Flow cytometry and cytogenetic and molecular genetic analysis performed at diagnosis and during the patient’s follow-up confirmed the presence of two clonally distinct B cell lymphomas, while the two T cell neoplasms were confirmed to be clonally related. We discuss the relationship between multiple neoplasms occurring in the same patient and the various possible risk factors involved in their development. 相似文献
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Minimal model of self-replicating nanocells: a physically embodied information-free scenario 总被引:1,自引:0,他引:1
Fellermann H Solé RV 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2007,362(1486):1803-1811
The building of minimal self-reproducing systems with a physical embodiment (generically called protocells) is a great challenge, with implications for both theory and applied sciences. Although the classical view of a living protocell assumes that it includes information-carrying molecules as an essential ingredient, a dividing cell-like structure can be built from a metabolism-container coupled system only. An example of such a system, modelled with dissipative particle dynamics, is presented here. This article demonstrates how a simple coupling between a precursor molecule and surfactant molecules forming micelles can experience a growth-division cycle in a predictable manner, and analyses the influence of crucial parameters on this replication cycle. Implications of these results for origins of cellular life and living technology are outlined. 相似文献
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Schulte G Bryja V Rawal N Castelo-Branco G Sousa KM Arenas E 《Journal of neurochemistry》2005,92(6):1550-1553
The Wnt family of lipoproteins regulates several aspects of the development of the nervous system. Recently, we reported that Wnt-3a enhances the proliferation of midbrain dopaminergic precursors and that Wnt-5a promotes their differentiation into dopaminergic neurones. Here we report the purification of hemagglutinin-tagged Wnt-5a using a three-step purification method similar to that previously described for Wnt-3a. Haemagglutinin-tagged Wnt-5a was biologically active and induced the differentiation of immature primary midbrain precursors into tyrosine hydroxylase-positive dopaminergic neurones. Using a substantia nigra-derived dopaminergic cell line (SN4741), we found that Wnt-5a, unlike Wnt-3a, did not promote beta-catenin phosphorylation or stabilization. However, both Wnt-5a and Wnt-3a activated dishevelled, as assessed by a phosphorylation-dependent mobility shift. Moreover, the activity of Wnt-5a on dishevelled was blocked by pre-treatment with acyl protein thioesterase-1, indicating that palmitoylation of Wnt-5a is necessary for its function. Thus, our results suggest that Wnt-3a and Wnt-5a, respectively, activate canonical and non-canonical Wnt signalling pathways in ventral midbrain dopaminergic cells. Furthermore, we identify dishevelled as a key player in transducing both Wnt canonical and non-canonical signals in dopaminergic cells. 相似文献