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1.
C Agundis  M Reyes  F Córdoba 《Experientia》1977,33(7):867-869
Proteolytic activity was detected outside dialysis bag filled with Bromelia hemisphaerica fruit juice. The dialysable protease was concentrated and purified from small molecular weight contaminants on Sephadex G-10 columns. Acrylamide gel electrophoresis of the dialysable protease, in the presence of SDS and 2-mercaptoethanol, demonstrated a single protein band of about 8000 daltons mol. wt. The same single band with identical mobility was shown with Hemisphaericin, the enzyme retained inside the dialysis bag. The small protease, named Hemisphaericin-D was antigenic in rabbits and the antibodies cross-reacted fully with Hemisphaericin. Hemisphaericin-D appears not to be a degradation product of Hemisphaericin.  相似文献   

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Summary Actinidin was rapidly inactivated by methylene blue-catalyzed photooxidation at pH 7.9 and 20°C. The rate of inactivation was pH-dependent and became slower at lower pH values, suggesting the involvement of a histidine residue in the inactivation.  相似文献   

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Type II transmembrane serine proteases (TTSPs) are a growing family of multidomain proteins. Among the TTSPs, a new subfamily of HAT/DESC1-like ( human airway trypsin-like protease/ differentially expressed in squamous cell carcinoma gene 1) proteases is emerging consisting so far of four members: DESC1–3 and HAT. The cDNA of a new member of this subfamily, named DESC4, was isolated from rat tongue tissue and characterised. Analysis of selected tissues by RT-PCR demonstrated expression of DESC4 in brain, colon, heart, liver, lung and tongue. At the cellular level, DESC4 expression is confined to epithelial cells within the cleft of the circumvallate papillae extending into the ducts of minor salivary glands, the respiratory epithelium of the nasal cavity and tear gland ducts of the eyes as analysed by in situ hybridisation of sensory organ tissues. In transfected mammalian cells, DESC4 is localised to the plasma membrane as shown by immunocytochemistry and subcellular fractionation experiments. Our results suggest that we have identified a protease that is an important constituent of sensory systems and other organs.Received 20 June 2004; received after revision 3 September 2004; accepted 17 September 2004  相似文献   

4.
梁带村遗址M27出土铜铁复合器的制作技术   总被引:3,自引:0,他引:3  
陕西韩城梁带村遗址第27号墓(M27)是梁带村两周墓地发现的唯一带有两墓道的大型墓葬, 是陕西地区建国以来发掘的未被盗掘的规模最大的周代墓葬. 墓葬保存完好, 随葬品丰富, 为研究墓葬的年代、墓主身份等级以及诸侯封国史提供了相当珍贵的实物资料. 尤其是该墓出土铁刃铜削和铁刃铜戈两件铁器是自河南三门峡虢国墓地及山西曲沃曲村遗址出土西周末~春秋早期铁器后的中原地区又一批年代最早的铁器, 具有重要学术意义. 本文利用金相组织观察和电子探针分析, 判定两件标本的铁质部分系采用块炼渗碳钢锻打而成, 然后通过铸接将铜质部分与铁质相结合, 加速器质谱碳十四测年为春秋早期. 根据梁带村遗址、三门峡虢国墓地与曲沃曲村遗址的地望, 本文提出等黄河中游的豫陕晋交界地区可能是我国中原冶铁技术起源地, 值得今后的考古学研究中注意.  相似文献   

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Zusammenfassung Beim extrakorporalen Kreislauf mit der Herz-Lungen-Maschine wurden die Veränderungen des Kininogengehalts im Plasma und ihre Beeinflussbarkeit mit einem Proteasen-Inhibitor untersucht. Der beobachtete Abfall des Kininogenspiegels im Plasma während und nach der Perfusion und die Hemmung der Kininogendepletion mit dem Proteasen-Inhibitor sprechen fÜr eine Aktivierung des Kininogen-Kinin-Systems im extrakorporalen Kreislauf. Beziehungen zur Aktivierung des fibrinolytischen Systems werden angenommen.  相似文献   

7.
Archive for History of Exact Sciences - Adolf Hurwitz’s estate contains a note from the early 1880s on the converse to Riemann’s proof of the functional equation for the zeta-function;...  相似文献   

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Hybridization of 257 mesophilic aeromonads revealed that the aerolysin gene is present in virtually all strains irrespective of origin of isolation. A probe comprising the promotor region was specific for a species now defined as Aeromonas trota sp. nov. Finally, isolation of a serine protease that is concomitantly expressed with aerolysin is described.  相似文献   

10.
Resumen Es describida la ultraestrutura de un segundo tipo de célula glandular mucosa que es encontrada en el pié ambulacrario de la estrella del marAsterina stellifera. Los gránulos secretores de esta célula tienen en su interior una ultraestrutura en forma de pequeños puntos densos y delicadas fibrillas, mas faltando una organizatión, principalmente comparada con la organizatión del otro tipo de granulo mucoso, también encontrado en el mismo pié ambulacrario.  相似文献   

11.
Zusammenfassung Es wird nachgewiesen, dass die menschliche Plazenta enzymatisch Cortisol in ein? 4-3-Ketosteroid mit Glycerol-Seitenkette, welches mehr polar ist als die 20α- und 20β-Derivate des 6-β-OH-Cortisols, umwandeln kann. Es scheint, dass die Plazenta dieses Steroid das aus dem Urin schwangerer Frauen isoliert wurde, selbst bildet.   相似文献   

12.
Summary Trypsin-like protease with wide spectrum of enzymatic activities have been isolated from cell-free medium from in vitro cultured human mammary carcinoma cells, and from peripheral blood lymphocytes of patients with mammary carcinoma cultured in presence of cell-membrane carcinoma-associated glycoprotein.  相似文献   

13.
The current findings from gill vascular cast preparations in the eel emphasize the division in each primary lamella of the afferent vasculature into two efferent pathways: an arterial pathway (via the secondary lamellae and the efferent branchial artery to the dorsal aorta), a venous pathway (via the central lamellar compartment and the branchial vein to the sinus venosus). By the same technique two antagonist mechanisms have been shown presumably controlling the blood flow in both pathways. 1. Acetylcholine increases the filling of the central lamellar compartment by constricting the efferent arterial sphincters and therefore increases the venous return. 2. Epinephrine impairs the filling of the central lamellar compartment (by acting on alpha receptors) and dilates the arterial pathway (by acting on beta receptors). Therefore the stimulation of these two synergic receptors by epinephrine increases the systemic blood flow.  相似文献   

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A A Hakim 《Experientia》1976,32(8):1057-1059
Trypsin-like protease with wide spectrum of enzymatic activities have been isolated from cell-free medium from in vivo cultured human mammary carcinoma cells, and from peripheral blood lymphocytes of patients with mammary carcinoma cultured in presence of cell-membrane carcinoma-associated glycoprotein.  相似文献   

16.
A recent finding of a novel class of retinol-active alcohol dehydrogenase (ADH) in frog prompted analysis of this activity in other vertebrate forms. Surprisingly, yet another and still more unrelated ADH was identified in chicken tissues. It was found to be a member of the aldo-keto reductase (AKR) enzyme family, not previously known as an ADH in vertebrates. Its terminal blocking group and the N-terminal segment, not assigned by protein and cDNA structure analysis, were determined by electrospray tandem mass spectrometry after protein isolation by two-dimensional gel electrophoresis. The N terminus is Acetyl-Ala- and the N-terminal segment contains two consecutive Asn residues. The results establish the new ADH enzyme of the AKR family and show the usefulness of combined gel separation and mass spectrometry in enzyme-characterization.  相似文献   

17.
Riassunto È stata determinata l'attività proteasica nelle differenti regioni della blastula e della gastrula diDiscoglossus pictus. Nella blastula non esiste una differenza di attività fra metà animale e vegetativa, quando si prenda come riferimento l'azoto citoplasmatico. Nella giovane gastrula il territorio presuntivo della corda e del sistema nervoso mostra una attività più elevata della epidermide presuntiva.  相似文献   

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Summary Forager (older) worker honeybees typically have lower midgut activity levels of chymotrypsin and trypsin than do house (younger) worker honeybees. A relation between the age correlated enzymic change and an age correlated decrease in pollen consumption is not clearly demonstrable.  相似文献   

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