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51.
There are more than 100 distinct types of cancer, and subtypes can be found within specific organs. Cancer progression is a complex multi-step process. These steps reflect alterations that drive the progressive transformation of normal cells into highly malignant ones. One critical step in tumor growth and invasion is the proteolytic processing of the extracellular matrix environment. The degradation of the extracellular matrix not only enables cell migration, invasion, and metastasis formation, but also affects cell behavior in multiple ways; on one hand by cleaving extracellular matrix bound growth factors and on the other hand by inhibiting angiogenesis into the tumor by liberating cryptic endogenous inhibitors of angiogenesis. Serine proteases and matrix metalloproteases are families of proteolytic enzymes involved in physiological and pathological extracellular matrix and basement membrane processing. In this review, we will focus on the role and activation of trypsinogens, a family of serine proteases, in cancer progression. 相似文献
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Hisashi Yagi Hideki Takeuchi Shiho Ogawa Naomi Ito Isao Sakane Kunihiro Hongo Tomohiro Mizobata Yuji Goto Yasushi Kawata 《Biochimica et Biophysica Acta - Proteins and Proteomics》2010,1804(10):2077-2087
α-Synuclein is one of the causative proteins of the neurodegenerative disorder, Parkinson's disease. Deposits of α-synuclein called Lewy bodies are a hallmark of this disorder, which is implicated in its progression. In order to understand the mechanism of amyloid fibril formation of α-synuclein in more detail, in this study we have isolated a specific, ~ 20 residue peptide region of the α-synuclein fibril core, using a combination of Edman degradation and mass-spectroscopy analyses of protease-resistant samples. Starting from this core peptide sequence, we then synthesized a series of peptides that undergo aggregation and fibril formation under similar conditions. Interestingly, in a derivative peptide where a crucial phenylalanine residue was changed to a glycine, the ability to initiate spontaneous fibril formation was abolished, while the ability to extend from preexisting fibril seeds was conserved. This fibril extension occurred irrespective of the source of the initial fibril seed, as demonstrated in experiments using fibril seeds of insulin, lysozyme, and GroES. This interesting ability suggests that this peptide might form the basis for a possible diagnostic tool useful in detecting the presence of various fibrillogenic factors. 相似文献
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Comparison of different biochemical and molecular methods for the identification of Vibrio parahaemolyticus 总被引:3,自引:0,他引:3
Croci L Suffredini E Cozzi L Toti L Ottaviani D Pruzzo C Serratore P Fischetti R Goffredo E Loffredo G Mioni R;Vibrio parahaemolyticus Working Group 《Journal of applied microbiology》2007,102(1):229-237
AIMS: Multicentre evaluation of biochemical and molecular methods for the identification of Vibrio parahaemolyticus. METHODS AND RESULTS: For the biochemical identification methods, API 20E and API 20NE and Alsina's scheme were evaluated in intra- and interlaboratory tests in order to determine the accuracy and concordance of each method. Both in intra- and interlaboratory tests, the Alsina's scheme showed the highest sensitivity (86% of correct identifications in the interlaboratory test). False-positive results were obtained by all methods (specificity was 95% for API 20E, 73% for API 20NE and 84% for Alsina's scheme) and concordance varied from 65% of API 20NE to 84% of API 20E. For the molecular identifications, polymerase chain reaction (PCR) for the detection of toxR gene, tl gene and pR72H fragment were tested on 30 strains by two laboratories. The PCR for toxR showed the highest inclusivity (96%), exclusivity (100%) and concordance (97%). CONCLUSIONS: Among the biochemical identification methods tested, the Alsina's scheme gave more reliable results; however, in order to avoid false-positive results, all the biochemical identifications should be confirmed by means of molecular methods. SIGNIFICANCE AND IMPACT OF THE STUDY: Availability of an efficient identification method of Vibrio parahaemolyticus to use in official control of fisheries products. 相似文献
54.
Aims: To isolate acid‐ and bile‐resistant Saccharomyces cerevisiae strains directly from food samples and to preliminarily select them on the basis of fundamental probiotic properties. Methods and Results: A rapid screening method allowed the isolation and selection of 20 acid‐ and bile‐resistant yeasts from foods, avoiding time‐consuming isolation steps. The strains were characterized for their specific survival in simulated gastric juice and in intestinal fluid after pre‐exposure at low pH. Ten isolates demonstrated a satisfactory survival percentage in intestinal fluid after pre‐exposure to gastric juice and appreciable lipolytic and proteolytic properties, as demonstrated by the API‐ZYM test. By using molecular methods five strains were identified as Saccharomyces cerevisiae, three as Candida spp., one as Candida pararugosa and one as Pichia spp. The Saccharomyces cerevisiae strains showed considerable probiotic properties, achieving a 80< % <90 survival through the simulated gastrointestinal tract, as well as interesting glucosidase activities. Conclusions: The research represents an efficient strategy to select and identify Saccharomyces cerevisiae strains with desirable acid and bile resistances. Significance and Impact of the Study: This paper reports the direct selection of potentially probiotic yeasts from foods and provides indications about the ability of Saccharomyces cerevisiae strains to survive conditions simulating the human gastrointestinal tract. 相似文献
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Yuki NiwaTakehiro Suzuki Naoshi DohmaeKazuo Umezawa Siro Simizu 《FEBS letters》2012,586(20):3601-3607
Cathepsin V (L2), a lysosomal cysteine protease, is a member of cathepsin family, relating to cancer invasion and metastasis. Cathepsin V contains two predicted N-glycosylation sites, but it has not been reported whether cathepsin V is glycosylated or not. In this study, we clarified the role of N-glycosylation of cathepsin V for its functions. We demonstrated that cathepsin V is N-glycosylated at both Asn221 and Asn292 using mass spectrometry and site-directed mutagenesis. N-glycosylation of cathepsin V was important for transportation to lysosome, secretion, and activity in HT1080 cells. These data demonstrated that functions of cathepsin V are controlled by N-glycosylation. 相似文献
57.
Peter J. Crick Jennifer Aponte T. William Bentley Ian Matthews Yuqin Wang William J. Griffiths 《Biochemical and biophysical research communications》2014
Oxysterols are oxidised forms of cholesterol that are intermediates in the synthesis of bile acids and steroid hormones. They are also ligands to nuclear and G protein-coupled receptors. Analysis of oxysterols in biological systems is challenging due to their low abundance coupled with their lack of a strong chromophore and poor ionisation characteristics in mass spectrometry (MS). We have previously used enzyme-assisted derivatisation for sterol analysis (EADSA) to identify and quantitate oxysterols in biological samples. This technique relies on tagging sterols with the Girard P reagent to introduce a charged quaternary ammonium group. Here, we have compared several modified Girard-like reagents and show that the permanent charge is vital for efficient MSn fragmentation. However, we find that the reagent can be extended to include sites for potential stable isotope labels without a loss of performance. 相似文献
58.
Yuchen Wang Kersti Karu Anna Meljon John Turton Joyce L. Yau Jonathan R. Seckl Yuqin Wang William J. Griffiths 《Biochemical and biophysical research communications》2014
24S,25-Epoxycholesterol is formed in a shunt of the mevalonate pathway that produces cholesterol. It is one of the most potent known activators of the liver X receptors and can inhibit sterol regulatory element-binding protein processing. Until recently analysis of 24S,25-epoxycholesterol at high sensitivity has been precluded by its thermal lability and lack of a strong chromophore. Here we report on the analysis of 24S,25-epoxycholesterol in rodent brain where its level was determined to be of the order of 0.4–1.4 μg/g wet weight in both adult mouse and rat. For comparison the level of 24S-hydroxycholesterol in brain of both rodents was of the order of 20 μg/g, while that of cholesterol in mouse was 10–20 mg/g. By exploiting knockout mice for the enzyme oxysterol 7α-hydroxylase (Cyp7b1) we show that this enzymes is important for the subsequent metabolism of the 24S,25-epoxide. 相似文献
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Résumé ChezPodisus maculiventris, les recherches ont montré qu'en règle générale, les activités enzymatiques au niveau du tube digestif augmentent progressivement
lorsque les larves atteignent le dernier stade. Le profil enzymatique des adultes, ressemble à celui des larves du 5e stade et est presque identique pour les deux sexes. Dans presque tous les cas on a observé qu'il y a un parallélisme entre
le système enzymatique des larves et celui des adultes d? probablement au fait que tous les stades du prédateur se nourrissent
avec le même type de nourriture. Cependant, l'arsenal enzymatique du tube digestif de prédateur semble être très riche en
activités phosphatasiques, estérasiques, aminopeptidasiques et osidasiques.
Summary Twenty enzymatic activities of the gut tissues of nymphs and adults ofPodisus maculiventris (Say) have been determined using mainly the API ZYM? micromethod. The activities registered increased progressively when the nymphs reached the last instar. The zymogrammes of the adults are almost identical to those obtained from the 5th-instar nymphs and almost no differences were recorded between the two sexes. From the recorded values it seems that there are a lot of similarities between the enzymatic system of nymphs and adults, due, very probably, to their identical feeding regimen. The enzymatic equipment of the gut tissues of this predator was found to be rich in phosphatase, esterase, aminopeptidase and carbohydrase activities.相似文献